scholarly journals Influence of depletion region width on performance of solar cell under sunlight concentration

2011 ◽  
Vol 6 ◽  
pp. 36-45 ◽  
Author(s):  
Khalaf AL Abdullah ◽  
Bashar Bakour
Keyword(s):  
Solar Cell ◽  
Depletion Region

scholarly journals A Study of the Relationship Analysis of Power Conversion and Changed Capacitance in the Depletion Region of Silicon Solar Cell

2013 ◽  
Vol 14 (4) ◽  
pp. 177-181 ◽  
Author(s):  
Do-Kyeong Kim ◽  
Yeong-Jun Oh ◽  
Sang-Hyun Kim ◽  
Kyeong-Jin Hong ◽  
Haeng-Yeon Jung ◽  
...  
Keyword(s):  
Solar Cell ◽  
Silicon Solar Cell ◽  
Power Conversion ◽  
Depletion Region ◽  
Relationship Analysis ◽  
The Relationship

Temperature Dependence of Electrical Characterization in n+ - CdS/ p - CdTe Thin Film Solar Cells – Study of Shallow/Deep Defects

2013 ◽  
Vol 1493 ◽  
pp. 161-167
Author(s):  
Poonam Rani Kharangarh ◽  
George E Georgiou ◽  
Ken K Chin
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Energy Levels ◽  
Depletion Region ◽  
Thin Film Solar Cells ◽  
Back Contact ◽  
Temperature Dependent ◽  
Trap Energy ◽  
Solar Cell Efficiency ◽  
Cell Efficiency

ABSTRACTFor CdTe there is no real distinction between defects and impurities exists when non-shallow dopants are used. These dopants act as beneficial impurities or detrimental carrier trapping centers. Unlike Si, the common assumption that the trap energy level Et is around the middle of the band-gap Ei, is not valid for thin film CdTe. Trap energy levels in CdTe band-gap can distributed with wide range of energy levels above EF. To identify the real role of traps and dopants that limit the solar cell efficiency, a series of samples were investigated in thin film n+-CdS/p-CdTe solar cell, made with evaporated Cu as a primary back contact. It is well known that process temperatures and defect distribution are highly related. This work investigates these shallow level impurities by using temperature dependent current-voltage (I-V-T) and temperature dependent capacitance-voltage (C-V-T) measurements. I-V-T and C-V-T measurements indicate that a large concentration of defects is located in the depletion region. It further suggests that while modest amounts of Cu enhance the cell performance by improving the back contact to CdTe, the high temperature (greater than ∼100°C) process condition degrade device quality and reduce the solar cell efficiency. This is possibly because of the well-established Cu diffusion from the back contact into CdTe. Hence, measurements were performed at lower temperatures (T = 150K to 350K). The observed traps are due to the thermal ionization of impurity centers located in the depletion region of p-CdTe/n+-CdS junction. For our n+-CdS/p-CdTe thin film solar cells, hole traps were observed that are verified by both the measurement techniques. These levels are identical to the observed trap levels by other characterization techniques.

Effect of Granularity on CuInSe2 Solar Cell Response

1990 ◽  
Vol 195 ◽  
Author(s):  
James R. Sites
Keyword(s):  
Surface Layer ◽  
Solar Cell ◽  
Diffusion Length ◽  
Surface States ◽  
Metal Films ◽  
Depletion Region ◽  
Proposed Model ◽  
Crystalline Surface ◽  
Recombination Current ◽  
Porous Grains

ABSTRACTPolycrystalline CuInSe2 solar cells, fabricated by evaporation or by selenization of metal films, are granular and relatively porous. Grains are a few hundred nanometers in dimension, and hence about 1% of the atoms are at a surface. Despite the granularity, quantum efficiency is quite high and implies a diffusion length exceeding the grain dimension. The primary photovoltaic loss is excessive forward recombination current. The proposed model consists of single crystal CuInSe2 granules with an indium rich surface layer. When properly passivated, the otherwise uncoordinated indium bonds are terminated by oxygen. However, residual non-passivated crystalline surface states distributed throughout the depletion region provide the paths for enhanced recombination.

Reducing Shockley–Read–Hall recombination losses in the depletion region of a solar cell by using a wide-gap emitter layer

2021 ◽  
Vol 130 (15) ◽  
pp. 153102
Author(s):  
Tetsuya Nakamura ◽  
Warakorn Yanwachirakul ◽  
Mitsuru Imaizumi ◽  
Masakazu Sugiyama ◽  
Hidefumi Akiyama ◽  
...  
Keyword(s):  
Solar Cell ◽  
Depletion Region ◽  
Emitter Layer ◽  
Wide Gap

scholarly journals Surface Texturing with Hemispherical Cavities to Improve Efficiency in Silicon Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
D. W. de Lima Monteiro ◽  
F. P. Honorato ◽  
R. F. de Oliveira Costa ◽  
L. P. Salles
Keyword(s):  
Solar Cell ◽  
Crystalline Silicon ◽  
Surface Texturing ◽  
Depletion Region ◽  
Antireflective Coatings ◽  
Frontal Surface ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Technology Processes ◽  
Profile Area

Improvement of solar-cell efficiency at a minimum possible cost addition is constantly sought, and this is often achieved at incremental percentage steps. Among a number of alternatives, antireflective coatings and surface texturing are the most prominent. This paper presents an alternative texturing method of crystalline silicon in an attempt to improve the efficiency of photon transmission through the surface and collection in the bulk. The method relies on anisotropic etching of bulk silicon and requires only a single oxide mask and two etching steps with a KOH or TMAH aqueous solution. The surface texture consists of smooth hemispherical cavities, which do not demand a lithographic mask or intricate technology processes to obtain the hemispherical cavities. This method can be applied to increase the profile area of the originally flat frontal surface exposed to light and consequently increase the effective width of the depletion region. The latter implies a higher probability of photon collection, contributing to the improvement of the conversion efficiency of the device. The textured nontilted silicon solar-cell transmittance under small solar incidence angles at dawn and sunset is improved compared to a flat surface, increasing the photocurrent.

A NEW APPROACH TO IDEAL AlGaAs MQW SOLAR CELLS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 778-781 ◽  
Author(s):  
J. C. RIMADA ◽  
L. HERNÁNDEZ
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Quantum Wells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Depletion Region ◽  
Open Circuit ◽  
Current Densities ◽  
Conversion Efficiencies ◽  
Open Circuit Voltages

A theoretical model has been developed which shows that the insertion of multi-quantum wells into the depletion region of a p-i(MQW)-n Al x Ga 1-x As solar cell can significantly enhance the conversion efficiencies. Open-circuit voltages, short-circuit current densities, I-V curves and conversion efficiencies have been calculated as functions of the well and barrier band gaps, width and depth of the wells, number of wells in the intrinsic region and the recombination rate in the interfaces. Particular emphasis is placed on calculation of absorption of the Al x Ga 1-x As quantum wells. These results are matched with p-i-n solar cells which are identical in all respects except that they do not have quantum wells. We demonstrated that for determined values of the studied parameters the conversion efficiencies of the quantum well solar cell is higher to corresponding cell without quantum wells.

A band-gap-graded CZTSSe solar cell with 12.3% efficiency

2016 ◽  
Vol 4 (26) ◽  
pp. 10151-10158 ◽  
Author(s):  
Kee-Jeong Yang ◽  
Dae-Ho Son ◽  
Shi-Joon Sung ◽  
Jun-Hyoung Sim ◽  
Young-Ill Kim ◽  
...  
Keyword(s):  
Solar Cell ◽  
Band Gap ◽  
Weight Ratio ◽  
Depletion Region

Using an appropriate SeS2/Se weight ratio, band gap grading was realized. By increasing the value ofVOCthrough band gap grading in the depletion region, a recordVOCdeficit of 0.576 V and an efficiency of 12.3% were obtained.

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