A. Dvurechenskii, A. Zinovieva, V. Zinovyev, A. Nenashev, Zh. V. Smagina, S. Teys, A. Shklyaev, S. Erenburg, S. Trubina, O. M. Borodavchenko, V. Zhivulko, A. Mudryi
The photoluminescence (PL) properties of combined Ge/Si structures representing a combination of large (200–250 nm) SiGe disk-like quantum dots (QDs) and the groups of smaller (40–50 nm) laterally ordered QDs grown on the nanodisk surface are studied. The experimental results are analyzed basing on the calculations of energy spectra, electron and hole wave functions. It is found that the strain accumulation in multi-layered structure is the main factor providing the room temperature PL. The new type of QD structures that should provide the observation of enhanced PL from SiGe QDs at room temperature is proposed. The structures represent the stacked compact groups of laterally aligned QDs incorporated in Si at the distance 30–40 nm above the large nanodisks.
{"title":"Photoluminescence from Ordered Ge/Si Quantum Dot Groups Grown on the Strain‐Patterned Substrates","authors":"A. Dvurechenskii, A. Zinovieva, V. Zinovyev, A. Nenashev, Zh. V. Smagina, S. Teys, A. Shklyaev, S. Erenburg, S. Trubina, O. M. Borodavchenko, V. Zhivulko, A. Mudryi","doi":"10.1002/PSSC.201700187","DOIUrl":"https://doi.org/10.1002/PSSC.201700187","url":null,"abstract":"The photoluminescence (PL) properties of combined Ge/Si structures representing a combination of large (200–250 nm) SiGe disk-like quantum dots (QDs) and the groups of smaller (40–50 nm) laterally ordered QDs grown on the nanodisk surface are studied. The experimental results are analyzed basing on the calculations of energy spectra, electron and hole wave functions. It is found that the strain accumulation in multi-layered structure is the main factor providing the room temperature PL. The new type of QD structures that should provide the observation of enhanced PL from SiGe QDs at room temperature is proposed. The structures represent the stacked compact groups of laterally aligned QDs incorporated in Si at the distance 30–40 nm above the large nanodisks.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"95 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75961321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexandra Levtchenko, R. Lachaume, Jérôme Michallon, S. Collin, J. Alvarez, S. D. Gall, Z. Djebbour, J. Kleider
Coupled optical/electrical simulations have been performed on solar cells consisting in arrays of p-i-n radial nanowires based on crystalline p-type silicon (c-Si) core/hydrogenated amorphous silicon (a-Si:H) shell heterojunctions. Three-dimensional (3D) optical calculations based on rigorous coupled wave analysis (RCWA) are firstly performed and then coupled to a semiconductor device simulator that exploits the radial symmetry of the nanowires. By varying either the doping concentration of the c-Si core, or the work function of the Al-doped ZnO (AZO) back contact we can separate and originally highlight the contribution to the cells performance of the nanowires themselves (the radial cell) from the planar part in between the nanowires (the planar cell). We show that the short-circuit current density (Jsc) only depends on the doping of the c-Si core indicating that it is mainly influenced by the radial cell. On the contrary the open-circuit voltage (Voc) is strongly affected by the back contact conditions (AZO work function), revealing an important impact of the interspacing between the nanowires on the characteristics of the entire nanowire array. We explain this strong influence of the back contact conditions by the fact that it determines the band-bending in the a-Si:H absorber shell touching the AZO, i.e. in the planar part. Therefore, it directly impacts the potential drop (Vbi) in the same area. For low AZO work functions, the dark current density (Jdark) is increased in the planar region, where Vbi is lower, which degrades the Voc of the entire cell.
{"title":"Coupling Optical and Electrical Modelling for the study of a-Si:H-based nanowire Array Solar Cells","authors":"Alexandra Levtchenko, R. Lachaume, Jérôme Michallon, S. Collin, J. Alvarez, S. D. Gall, Z. Djebbour, J. Kleider","doi":"10.1002/PSSC.201700181","DOIUrl":"https://doi.org/10.1002/PSSC.201700181","url":null,"abstract":"Coupled optical/electrical simulations have been performed on solar cells consisting in arrays of p-i-n radial nanowires based on crystalline p-type silicon (c-Si) core/hydrogenated amorphous silicon (a-Si:H) shell heterojunctions. Three-dimensional (3D) optical calculations based on rigorous coupled wave analysis (RCWA) are firstly performed and then coupled to a semiconductor device simulator that exploits the radial symmetry of the nanowires. By varying either the doping concentration of the c-Si core, or the work function of the Al-doped ZnO (AZO) back contact we can separate and originally highlight the contribution to the cells performance of the nanowires themselves (the radial cell) from the planar part in between the nanowires (the planar cell). We show that the short-circuit current density (Jsc) only depends on the doping of the c-Si core indicating that it is mainly influenced by the radial cell. On the contrary the open-circuit voltage (Voc) is strongly affected by the back contact conditions (AZO work function), revealing an important impact of the interspacing between the nanowires on the characteristics of the entire nanowire array. We explain this strong influence of the back contact conditions by the fact that it determines the band-bending in the a-Si:H absorber shell touching the AZO, i.e. in the planar part. Therefore, it directly impacts the potential drop (Vbi) in the same area. For low AZO work functions, the dark current density (Jdark) is increased in the planar region, where Vbi is lower, which degrades the Voc of the entire cell.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"56 1","pages":"1700181"},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81000141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. D. Iacovo, Carlo Venettacci, L. Colace, L. Scopa, S. Foglia
Flame sensing and early fire detection are primary features in modern security and surveillance systems. Optical detection systems are widely developed and offer the highest sensitivity and selectivity but they are still expensive and show a high power budget. Here we propose a low-cost, low-power flame detector based on PbS colloidal quantum dots. We show detector operation with a 21 nW total power dissipation and the ability to detect the flame of a candle at 20 m with a 5 dB signal to noise ratio (SNR).
{"title":"High Sensitivity Flame Sensor Based on PbS Colloidal Quantum Dots","authors":"A. D. Iacovo, Carlo Venettacci, L. Colace, L. Scopa, S. Foglia","doi":"10.1002/PSSC.201700186","DOIUrl":"https://doi.org/10.1002/PSSC.201700186","url":null,"abstract":"Flame sensing and early fire detection are primary features in modern security and surveillance systems. Optical detection systems are widely developed and offer the highest sensitivity and selectivity but they are still expensive and show a high power budget. Here we propose a low-cost, low-power flame detector based on PbS colloidal quantum dots. We show detector operation with a 21 nW total power dissipation and the ability to detect the flame of a candle at 20 m with a 5 dB signal to noise ratio (SNR).","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"161 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78007507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, there has been increased interest in the use of flexible substrates for the fabrication of Cu(In,Ga)Se2 solar cells due to their light weight and easy application. This work focuses on the use of 150 μm thick Mo foils as substrates which has not received much attention compared to other metals such as Ti and Stainless Steel although the coefficient of expansion of Mo better matches that of CIGS. Interestingly, Mo foil can be used as both the substrate and back contact which reduces the manufacturing steps of this type of solar cell. The CIGS absorbers herein were realized by a 3-stage coevaporation process. This work studies the impact of temperature, Na incorporation and the optimization of the Ga gradient on the cell performance using different characterization techniques such as XRD, GD-OES, and IV measurements. Efficiencies up to 14%, with Voc = 0.60 V, Jsc = 34.1 mA cm−2 and FF = 70.4% have been obtained.
近年来，人们对使用柔性衬底制造Cu(in,Ga)Se2太阳能电池越来越感兴趣，因为它们重量轻，易于应用。本文的工作重点是使用150 μm厚的Mo箔作为衬底，尽管Mo的膨胀系数与CIGS的膨胀系数更匹配，但与Ti和不锈钢等其他金属相比，这种衬底并未受到太多关注。有趣的是，钼箔既可以用作衬底，也可以用作背触点，从而减少了这种类型太阳能电池的制造步骤。CIGS吸收器采用三段共蒸发工艺实现。本文采用不同的表征技术，如XRD、GD-OES和IV测量，研究了温度、Na掺入和Ga梯度优化对电池性能的影响。效率高达14%，Voc = 0.60 V, Jsc = 34.1 mA cm - 2, FF = 70.4%。
{"title":"Flexible Cu(In,Ga)Se2 Based Solar Cells Using Molybdenum Foils as Substrate","authors":"M. Stanley, M. Jubault, F. Donsanti, N. Naghavi","doi":"10.1002/PSSC.201700174","DOIUrl":"https://doi.org/10.1002/PSSC.201700174","url":null,"abstract":"Recently, there has been increased interest in the use of flexible substrates for the fabrication of Cu(In,Ga)Se2 solar cells due to their light weight and easy application. This work focuses on the use of 150 μm thick Mo foils as substrates which has not received much attention compared to other metals such as Ti and Stainless Steel although the coefficient of expansion of Mo better matches that of CIGS. Interestingly, Mo foil can be used as both the substrate and back contact which reduces the manufacturing steps of this type of solar cell. The CIGS absorbers herein were realized by a 3-stage coevaporation process. This work studies the impact of temperature, Na incorporation and the optimization of the Ga gradient on the cell performance using different characterization techniques such as XRD, GD-OES, and IV measurements. Efficiencies up to 14%, with Voc = 0.60 V, Jsc = 34.1 mA cm−2 and FF = 70.4% have been obtained.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77120727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giri Wahyu Alam, E. Pihan, B. Marie, N. Mangelinck-Noël
In High Performance Multi-Crystalline-Silicon (HPMC-Si) ingots, small seed grains generate grain boundaries that can terminate the propagation of dislocation clusters. Here, we focus on the seed template formation and its impact on the initial growth by directional solidification utilizing metallography, photoluminescence, and EBSD analysis. In the seed region, two randomly oriented grain morphologies are found: a genuine nonmelted seed from the poly-Si chunks, and a re-solidified infiltrated molten silicon region. All grains grow by epitaxy on the seed grains and grains grown from wider grains in the seed, reach a higher solidification height.
{"title":"Impact of the Seed Layer Morphology on the Initial Growth of HPMC‐Si Ingot","authors":"Giri Wahyu Alam, E. Pihan, B. Marie, N. Mangelinck-Noël","doi":"10.1002/PSSC.201700177","DOIUrl":"https://doi.org/10.1002/PSSC.201700177","url":null,"abstract":"In High Performance Multi-Crystalline-Silicon (HPMC-Si) ingots, small seed grains generate grain boundaries \u0000that can terminate the propagation of dislocation clusters. Here, we focus on the seed template formation and its impact on the initial growth by directional solidification utilizing metallography, photoluminescence, and EBSD analysis. In the seed region, two randomly oriented grain morphologies are found: a genuine nonmelted seed from the poly-Si chunks, and a re-solidified infiltrated molten silicon region. All grains grow by epitaxy on the seed grains and grains grown from wider grains in the seed, reach a higher solidification height.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"95 1","pages":"1700177"},"PeriodicalIF":0.0,"publicationDate":"2017-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75972609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To stack Ge quantum dots (QDs) in a multilayer structure without undesirable enlargement of the QDs, the effects of both Si1−xCx spacer on a strain compensation of the embedded QDs and a sub-monolayer (ML) carbon (C) mediation on a formation of the Volmer-Weber (VW)-mode Ge QDs on the Si1−xCx spacer were investigated. In a Si1−xCx/Ge/Si(100) structure, lattice rexation of the embedded QDs was kept about 80% at x = 0.015. This maintaining the state of high relaxation attributed to a tensile strain from the Si1−xCx layer grown on a surface of a Si substrate around the QDs. In addition, by utilizing an analysis of Kelvin probe force microscopy, it was revealed that the sub-ML C mediation of 0.25 ML and over is effective to form the VW-mode Ge QDs on the Si1−xCx spacer. This is because the promotion of subdivision effect for the formation of the QDs via C mediation was also effective on the Si1−xCx surface. At C = 0.25 and 0.5 ML, diameter and density of second QDs were about 22 nm and 1.5 × 1011 cm−2, respectively. These results pave the way to stack the VW-mode Ge QDs in the multilayer structure without enlargement of the QDs.
{"title":"Formation and Strain Analysis of Stacked Ge Quantum Dots With Strain‐Compensating Si1−xCx Spacer","authors":"Y. Itoh, T. Kawashima, K. Washio","doi":"10.1002/PSSC.201700197","DOIUrl":"https://doi.org/10.1002/PSSC.201700197","url":null,"abstract":"To stack Ge quantum dots (QDs) in a multilayer structure without undesirable enlargement of the QDs, the effects of both Si1−xCx spacer on a strain compensation of the embedded QDs and a sub-monolayer (ML) carbon (C) mediation on a formation of the Volmer-Weber (VW)-mode Ge QDs on the Si1−xCx spacer were investigated. In a Si1−xCx/Ge/Si(100) structure, lattice rexation of the embedded QDs was kept about 80% at x = 0.015. This maintaining the state of high relaxation attributed to a tensile strain from the Si1−xCx layer grown on a surface of a Si substrate around the QDs. In addition, by utilizing an analysis of Kelvin probe force microscopy, it was revealed that the sub-ML C mediation of 0.25 ML and over is effective to form the VW-mode Ge QDs on the Si1−xCx spacer. This is because the promotion of subdivision effect for the formation of the QDs via C mediation was also effective on the Si1−xCx surface. At C = 0.25 and 0.5 ML, diameter and density of second QDs were about 22 nm and 1.5 × 1011 cm−2, respectively. These results pave the way to stack the VW-mode Ge QDs in the multilayer structure without enlargement of the QDs.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89047903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, undoped and 1–5 at.% In-doped SnO2-δ films are deposited onto glass substrates at 350 °C by spray pyrolysis technique. The influence of dopant concentration is investigated using X-ray diffraction (XRD), UV-Visible spectroscopy, and Hall Effect measurements using van der Pauw method. X-ray diffraction studies indicate that all films had preferred orientation along (200) plane and are polycrystalline with tetragonal rutile structure. The calculated average crystallite sizes increased after doping. Substitution of In into SnO2-δ thin films can be confirmed by the shifting of the peaks in the XRD patterns. Optical transmittance of the films show high average transparency ∼80–90% in the visible region. Hall measurements show that the conduction type is dependent on In content. For low-doped films (In ≤3 at.%), the films are n-type, while at higher doping concentration the films are p-type. The calculated values of the mean free path are very small compared to the average crystallite sizes calculated using XRD measurements. Therefore, we suggest that ionized and/or neutral impurity scattering are the main scattering mechanisms in these films. The above-mentioned characteristics render these In-doped SnO2 films potential candidates for their use in light-emitting diode and in optoelectronic devices, with the advantage that they are prepared by a simple and economical technique.
{"title":"Investigation of Structural, Optical, and Electrical Properties of In‐Doped SnO2 Thin Films Deposited by Spray Pyrolysis","authors":"A. Hadri, A. E. Hat, M. Sekkati, A. Mzerd","doi":"10.1002/PSSC.201700189","DOIUrl":"https://doi.org/10.1002/PSSC.201700189","url":null,"abstract":"In this work, undoped and 1–5 at.% In-doped SnO2-δ films are deposited onto glass substrates at 350 °C by spray pyrolysis technique. The influence of dopant concentration is investigated using X-ray diffraction (XRD), UV-Visible spectroscopy, and Hall Effect measurements using van der Pauw method. X-ray diffraction studies indicate that all films had preferred orientation along (200) plane and are polycrystalline with tetragonal rutile structure. The calculated average crystallite sizes increased after doping. Substitution of In into SnO2-δ thin films can be confirmed by the shifting of the peaks in the XRD patterns. Optical transmittance of the films show high average transparency ∼80–90% in the visible region. Hall measurements show that the conduction type is dependent on In content. For low-doped films (In ≤3 at.%), the films are n-type, while at higher doping concentration the films are p-type. The calculated values of the mean free path are very small compared to the average crystallite sizes calculated using XRD measurements. Therefore, we suggest that ionized and/or neutral impurity scattering are the main scattering mechanisms in these films. The above-mentioned characteristics render these In-doped SnO2 films potential candidates for their use in light-emitting diode and in optoelectronic devices, with the advantage that they are prepared by a simple and economical technique.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76192961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the last few years, an accelerated trend toward the miniaturization of nanoscale circuits has been recorded. In fact, this has been reflected by numerous enhancements at different levels of multi-gate structures such as the channel body or the gate material. Our aim in this work is to investigate the reliability performance of junctionless DG MOSFET including graded channel aspect. The behavior of the considered device is analyzed numerically using ATLAS-2D simulator, where degradation phenomena are accounted for in the model. The variation of some analog/RF criteria namely the transconductance and cut-off frequency are established in terms of the channel length and traps density. The obtained responses indicate the superior immunity of the graded channel device against traps-induced degradation in comparison to the conventional structure. Thus, this work can offer more insights regarding the benefit of adopting the channel doping engineering for future nanoscale electronic applications.
{"title":"Improved Reliability Performance of Junctionless Nanoscale DG MOSFET with Graded Channel Doping Engineering","authors":"T. Bentrcia, F. Djeffal, D. Arar, Elasaad Chebaki","doi":"10.1002/PSSC.201700147","DOIUrl":"https://doi.org/10.1002/PSSC.201700147","url":null,"abstract":"In the last few years, an accelerated trend toward the miniaturization of nanoscale circuits has been recorded. In fact, this has been reflected by numerous enhancements at different levels of multi-gate structures such as the channel body or the gate material. Our aim in this work is to investigate the reliability performance of junctionless DG MOSFET including graded channel aspect. The behavior of the considered device is analyzed numerically using ATLAS-2D simulator, where degradation phenomena are accounted for in the model. The variation of some analog/RF criteria namely the transconductance and cut-off frequency are established in terms of the channel length and traps density. The obtained responses indicate the superior immunity of the graded channel device against traps-induced degradation in comparison to the conventional structure. Thus, this work can offer more insights regarding the benefit of adopting the channel doping engineering for future nanoscale electronic applications.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85836047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a new particle swarm optimization-based approach is proposed for the geometrical optimization of the nanowires solar cells to achieve improved optical performance. The proposed hybrid approach combines the 3-D numerical analysis using accurate solutions of Maxwell's equations and metaheuristic investigation to boost the solar cell total absorbance efficiency. Our purpose resides on modulating the electric field and increasing the light trapping capability by optimizing the radial solar cell geometrical parameters. Moreover, a comprehensive study of vertical core-shell nanowire arrays optical parameters such as the integral absorption, reflection, and total absorbance efficiency is carried out, in order to reveal the optimized radial solar cells optical performance for low-cost photovoltaic applications. We find that the proposed hybrid approach plays a crucial role in improving the nanowires solar cells optical performance, where the optimized design exhibits superior total absorbance efficiency and lower total reflection in comparison with those provided by the conventional planar design. The obtained results make the proposed global optimization approach valuable for providing high-efficiency nanowires solar cells.
{"title":"Efficiency Enhancement of a-Si:H/c-Si-Based Radial Solar Cell by Optimizing the Geometrical and Electrical Parameters","authors":"H. Ferhati, F. Djeffal, D. Arar, Z. Dibi","doi":"10.1002/PSSC.201700146","DOIUrl":"https://doi.org/10.1002/PSSC.201700146","url":null,"abstract":"In this paper, a new particle swarm optimization-based approach is proposed for the geometrical optimization of the nanowires solar cells to achieve improved optical performance. The proposed hybrid approach combines the 3-D numerical analysis using accurate solutions of Maxwell's equations and metaheuristic investigation to boost the solar cell total absorbance efficiency. Our purpose resides on modulating the electric field and increasing the light trapping capability by optimizing the radial solar cell geometrical parameters. Moreover, a comprehensive study of vertical core-shell nanowire arrays optical parameters such as the integral absorption, reflection, and total absorbance efficiency is carried out, in order to reveal the optimized radial solar cells optical performance for low-cost photovoltaic applications. We find that the proposed hybrid approach plays a crucial role in improving the nanowires solar cells optical performance, where the optimized design exhibits superior total absorbance efficiency and lower total reflection in comparison with those provided by the conventional planar design. The obtained results make the proposed global optimization approach valuable for providing high-efficiency nanowires solar cells.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79883854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High sensitivity photodetectors based on PbS colloidal quantum dots have been demonstrated by several research groups in the last years with performance comparable to commercial III–V semiconductor devices. Nevertheless, investigation of the noise performance of such new photodetectors is still lacking. Here we report on the characterization of PbS colloidal quantum dot near infrared photoconductors including a preliminary analysis of noise power spectra. Devices have been characterized focusing on the low frequency regime (up to 10 kHz) investigating the noise dependence on the voltage bias.
{"title":"PbS Colloidal Quantum Dot Near Infrared Photoconductors: DC and Noise Characterization","authors":"L. Colace, A. D. Iacovo, Carlo Venettacci","doi":"10.1002/pssc.201700185","DOIUrl":"https://doi.org/10.1002/pssc.201700185","url":null,"abstract":"High sensitivity photodetectors based on PbS colloidal quantum dots have been demonstrated by several research groups in the last years with performance comparable to commercial III–V semiconductor devices. Nevertheless, investigation of the noise performance of such new photodetectors is still lacking. Here we report on the characterization of PbS colloidal quantum dot near infrared photoconductors including a preliminary analysis of noise power spectra. Devices have been characterized focusing on the low frequency regime (up to 10 kHz) investigating the noise dependence on the voltage bias.","PeriodicalId":20065,"journal":{"name":"Physica Status Solidi (c)","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74957038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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