Moving Photocarrier Grating Technique for Mobility and Lifetime Measurements in Amorphous Semiconductors

1994 ◽  
Vol 336 ◽  
Author(s):  
M. Hundhausen ◽  
U. Haken ◽  
L. Ley
Keyword(s):  
Carrier Lifetime ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Amorphous Semiconductors ◽  
Small Signal ◽  
Lifetime Measurements ◽  
Material Parameters ◽  
Continuity Equations

ABSTRACTIn this paper we describe a new method for the determination of the carrier lifetime (r) and the carrier Mobilities (μn, μp) in semiconductors. This technique utilizes a moving intensity grating that is generated by superposition of frequency shifted laser beams for the illumination of the sample. The Material parameters are extracted from the short circuit current in the sample induced by the moving grating as a function of it's velocity (vgr). We solve the continuity equations and Poisson's equation in the small signal approach for the modulated electron and hole densities and show how these densities result in an electric field that in turn acts on the electrons and holes in order to yield a short circuit current density jsc. From a fit of this expression for jsc to experimental data we determine μn, μp and τ.

scholarly journals Effects of Incoherent Front Cover Glass on Current-Voltage Characteristics of Cu(In,Ga)Se2 Solar Cells: Investigation into Calculation Accuracy for Cover Glass Modeled as Optically Coherent or Incoherent

2020 ◽  
Vol 10 (9) ◽  
pp. 3312
Author(s):  
Jihye Baik ◽  
Junbum Park ◽  
Gyeongjun Lee ◽  
Sungchul Kim ◽  
Jungho Kim
Keyword(s):  
Solar Cells ◽  
Numerical Solutions ◽  
Short Circuit ◽  
Optical Power ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Cover Glass ◽  
Front Cover ◽  
Continuity Equations ◽  
Current Voltage

We numerically investigate the effects of an incoherent front cover glass on the current–voltage (J–V) characteristics of a Cu(In,Ga)Se2 (CIGS) solar cell using an integrated optoelectronic model. A 3-mm cover glass—the thickness of which was larger than the coherence length of sunlight—was incoherently modeled based on the equispaced thickness averaging method, where coherent simulation results of the wave equation were averaged over a set of equispaced phase thicknesses. The changes in optical power dissipation, absorptivity and electron–hole pair generation rate were calculated depending on the variation of the equispaced phase thickness. The calculation results of the J–V curves were obtained through numerical solutions of the coupled Poisson and continuity equations. By comparing the J–V curves calculated between coherently and incoherently modeled cover glass, we obtained a maximum ±0.54% deviation of the short-circuit current density. This demonstrates that the front cover glass should be modeled as optically incoherent to improve the calculation accuracy of the electrical J–V curves as well as the optical absorption characteristics in the optoelectronic modeling of CIGS solar cells.

scholarly journals Laser Enhanced Hydrogen Passivation of Silicon Wafers

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Lihui Song ◽  
Alison Wenham ◽  
Sisi Wang ◽  
Phillip Hamer ◽  
Mohammad Shakil Ahmmed ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Short Circuit ◽  
Minority Carrier Lifetime ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Silicon Wafers ◽  
Hydrogenation Process ◽  
Carrier Lifetimes

The application of lasers to enable advanced hydrogenation processes with charge state control is explored. Localised hydrogenation is realised through the use of lasers to achieve localised illumination and heating of the silicon material and hence spatially control the hydrogenation process. Improvements in minority carrier lifetime are confirmed in the laser hydrogenated regions using photoluminescence (PL) imaging. However with inappropriate laser settings a localised reduction in minority carrier lifetime can result. It is observed that high illumination intensities and rapid cooling are beneficial for achieving improvements in minority carrier lifetimes through laser hydrogenation. The laser hydrogenation process is then applied to finished screen-printed solar cells fabricated on seeded-cast quasi monocrystalline silicon wafers. The passivation of dislocation clusters is observed with clear improvements in quantum efficiency, open circuit voltage, and short circuit current density, leading to an improvement in efficiency of 0.6% absolute.

Determination of the Efficiency Enhancement Due to Scattering from Rough TCO Contact for a-Si:H P-I-N Solar Cells

1987 ◽  
Vol 95 ◽  
Author(s):  
C. Walker ◽  
R. E. Hollingsworth ◽  
A. Madan
Keyword(s):  
Solar Cells ◽  
Optical Thickness ◽  
Short Circuit ◽  
Transparent Conducting Oxide ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Efficiency Enhancement ◽  
Glass Substrates ◽  
Transparent Conducting

AbstractA-Si:H p-i-n solar cells were deposited on textured transparent conducting oxide coated glass substrates to experimentally determine the enhancement in the short circuit current density. It was found that the optical thickness can be increased by a factor from 3 to 5. These results agree reasonably well with the predictions of optical enhancement theory.

Determining the exciton diffusion length of copper phthalocyanine in operating planar-heterojunction organic solar cells

2020 ◽  
Vol 89 (3) ◽  
pp. 30201 ◽  
Author(s):  
Xi Guan ◽  
Shiyu Wang ◽  
Wenxing Liu ◽  
Dashan Qin ◽  
Dayan Ban
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Diffusion Length ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Thick Layer ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Organic solar cells based on planar copper phthalocyanine (CuPc)/C60 heterojunction have been characterized, in which a 2 nm-thick layer of bathocuproine (BCP) is inserted into the CuPc layer. The thin layer of BCP allows hole current to tunnel it through but blocks the exciton diffusion, thereby altering the steady-state exciton profile in the CuPc zone (zone 1) sandwiched between BCP and C60. The short-circuit current density (JSC) of device is limited by the hole-exciton scattering effect at the BCP/CuPc (zone 1) interface. Based on the variation of JSC with the width of zone 1, the exciton diffusion length of CuPc is deduced to be 12.5–15 nm. The current research provides an easy and helpful method to determine the exciton diffusion lengths of organic electron donors.

scholarly journals The Influence of the Thickness of Compact TiO2 Electron Transport Layer on the Performance of Planar CH3NH3PbI3 Perovskite Solar Cells

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3295
Author(s):  
Andrzej Sławek ◽  
Zbigniew Starowicz ◽  
Marek Lipiński
Keyword(s):  
Solar Cells ◽  
Electron Transport ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Perovskite Solar Cells ◽  
Precursor Solution ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Transport Layer ◽  
Electron Transport Layer

In recent years, lead halide perovskites have attracted considerable attention from the scientific community due to their exceptional properties and fast-growing enhancement for solar energy harvesting efficiency. One of the fundamental aspects of the architecture of perovskite-based solar cells (PSCs) is the electron transport layer (ETL), which also acts as a barrier for holes. In this work, the influence of compact TiO2 ETL on the performance of planar heterojunction solar cells based on CH3NH3PbI3 perovskite was investigated. ETLs were deposited on fluorine-doped tin oxide (FTO) substrates from a titanium diisopropoxide bis(acetylacetonate) precursor solution using the spin-coating method with changing precursor concentration and centrifugation speed. It was found that the thickness and continuity of ETLs, investigated between 0 and 124 nm, strongly affect the photovoltaic performance of PSCs, in particular short-circuit current density (JSC). Optical and topographic properties of the compact TiO2 layers were investigated as well.

High short-circuit current density in a non-toxic Bi2S3 Quantum dot sensitized solar cell

2021 ◽  
pp. 100783
Author(s):  
Christopher Rosiles-Perez ◽  
Sirak Sidhik ◽  
Luis Ixtilico-Cortés ◽  
Fernando Robles-Montes ◽  
Tzarara López-Luke ◽  
...  
Keyword(s):  
Solar Cell ◽  
Quantum Dot ◽  
Current Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density

scholarly journals CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Early Years ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.

scholarly journals Over 30% efficiency bifacial 4-terminal perovskite-heterojunction silicon tandem solar cells with spectral albedo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangho Kim ◽  
Thanh Thuy Trinh ◽  
Jinjoo Park ◽  
Duy Phong Pham ◽  
Sunhwa Lee ◽  
...  
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Solar Spectrum ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Production Costs ◽  
White Sand ◽  
Reflected Light

AbstractWe developed and designed a bifacial four-terminal perovskite (PVK)/crystalline silicon (c-Si) heterojunction (HJ) tandem solar cell configuration albedo reflection in which the c-Si HJ bottom sub-cell absorbs the solar spectrum from both the front and rear sides (reflected light from the background such as green grass, white sand, red brick, roofing shingle, snow, etc.). Using the albedo reflection and the subsequent short-circuit current density, the conversion efficiency of the PVK-filtered c-Si HJ bottom sub-cell was improved regardless of the PVK top sub-cell properties. This approach achieved a conversion efficiency exceeding 30%, which is higher than those of both the top and bottom sub-cells. Notably, this efficiency is also greater than the Schockley–Quiesser limit of the c-Si solar cell (approximately 29.43%). The proposed approach has the potential to lower industrial solar cell production costs in the near future.

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