Enhanced Charge Extraction in Metal–Perovskite–Metal Back-Contact Solar Cell Structure Through Electrostatic Doping: A Numerical Study

Utilization of Tin Halide as an absorber in Perovskite solar cells is immensely recognized as a substitute of lead halide absorber because of lead material’s toxicity. Also, Tin halide based Perovskites possess a potential for higher quantum efficiency because of their enhanced light absorption capability due to the wide-ranging absorption spectrum in the visible region with a comparatively lower bandgap of 1.3 eV than lead-based Perovskites. In the present work, glass/ transparent conductive oxide (TCO)/ titanium dioxide (buffer)/ tin halide Perovskite (Absorber)/ cuprous thiocyanate (HTM)/ Metal back solar cell structure has been designed and simulated by SCAPS software which yields Power Conversion Efficiency (PCE) of 28.32% and Fill Factor (FF) of 85.17%. The effect of total defect density, thickness, Valance Band Effective Density of States (VBEDS) and Conduction Band Effective Density of States (CBEDS) for an absorber layer has been analyzed. It has been observed that VBEDS variation has achieved PCE and FF to a significant extent i.e. up to 32.47% PCE and 85.86% FF

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Back contact band offset study of Mo-CZTS based solar cell structure by using XPS/UPS techniques

2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC) ◽

10.1109/pvsc.2015.7355623 ◽

2015 ◽

Cited By ~ 3

Author(s):

Tara P. Dhakal ◽

Steve Harvey ◽

Maikel van Hest ◽

Glenn Teeter

Keyword(s):

Solar Cell ◽

Cell Structure ◽

Band Offset ◽

Back Contact ◽

Solar Cell Structure

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A Numerical Investigation on the Combined Effects of MoSe2 Interface Layer and Graded Bandgap Absorber in CIGS Thin Film Solar Cells

Coatings ◽

10.3390/coatings11080930 ◽

2021 ◽

Vol 11 (8) ◽

pp. 930

Author(s):

Fazliyana Za’abar ◽

Yulisa Yusoff ◽

Hassan Mohamed ◽

Siti Abdullah ◽

Ahmad Mahmood Zuhdi ◽

...

Keyword(s):

Thin Film ◽

Solar Cell ◽

Cell Structure ◽

Absorber Layer ◽

Back Contact ◽

Cigs Solar Cell ◽

Cigs Thin Film ◽

Solar Cell Structure ◽

Mose2 Layer ◽

Graded Bandgap

The influence of Molybdenum diselenide (MoSe2) as an interfacial layer between Cu(In,Ga)Se2 (CIGS) absorber layer and Molybdenum (Mo) back contact in a conventional CIGS thin-film solar cell was investigated numerically using SCAPS-1D (a Solar Cell Capacitance Simulator). Using graded bandgap profile of the absorber layer that consist of both back grading (BG) and front grading (FG), which is defined as double grading (DG), attribution to the variation in Ga content was studied. The key focus of this study is to explore the combinatorial effects of MoSe2 contact layer and Ga grading of the absorber to suppress carrier losses due to back contact recombination and resistance that usually occur in case of standard Mo thin films. Thickness, bandgap energy, electron affinity and carrier concentration of the MoSe2 layer were all varied to determine the best configuration for incorporating into the CIGS solar cell structure. A bandgap grading profile that offers optimum functionality in the proposed configuration with additional MoSe2 layer has also been investigated. From the overall results, CIGS solar cells with thin MoSe2 layer and high acceptor doping concentration have been found to outperform the devices without MoSe2 layer, with an increase in efficiency from 20.19% to 23.30%. The introduction of bandgap grading in the front and back interfaces of the absorber layer further improves both open-circuit voltage (VOC) and short-circuit current density (JSC), most likely due to the additional quasi-electric field beneficial for carrier collection and reduced back surface and bulk recombination. A maximum power conversion efficiency (PCE) of 28.06%, fill factor (FF) of 81.89%, JSC of 39.45 mA/cm2, and VOC of 0.868 V were achieved by optimizing the properties of MoSe2 layer and bandgap grading configuration of the absorber layer. This study provides an insight into the different possibilities for designing higher efficiency CIGS solar cell structure through the manipulation of naturally formed MoSe2 layer and absorber bandgap engineering that can be experimentally replicated.

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