Boosting CZTSSe Solar Cell Efficiency by Back Surface Field Layer

In this work, a simulation of the CZTSSe (Cu2ZnSn(S,Se)4) solar cell with Al/ZnO:Al/ZnO(i)/CdS/ CZTSSe/Mo structure have been studied using the SCAPS-1D (Solar Cell Capacitance Simulator in one Dimension). The simulation results have been validated with real experimental results. Next, a novel structure is proposed in which a back surface field (BSF) layer is inserted in order to boost the solar cell performance, a CZTSSe layer has been used as (BSF) layer. The efficiency of CZTSSe solar cell increases from 12.3 % to 15.3 % by inserting a BSF layer. Finally, an optimization of different physical parameters (Thickness and doping concentration) of BSF layer has been done, and the optimum values are determined. In this research work, the proposed structure of CZTSSe solar cells with optimum parameters showed higher functional properties, The maximum value of efficiency achieved was 16.98 % with Jsc = 36.31 mA/cm2, Voc = 0.69 V, and FF = 69.60% under 1.5G AM illumination

Numerical Simulation of Luminescent Downshifting in Top Cell of Monolithic Tandem Solar Cells

The increase in the conversion efficiency of monolithic tandem solar cells is limited by the short-circuit current density matching between the top and the bottom cells. Generally, the top cell presents the lowest current in the two subcells. In this paper, in order to increase the short-circuit current density in the top cell, we present a theoretical survey of the luminescence downshifting (LDS) approach for the design of monolithic tandem solar cells. The photovoltaic (PV) glass encapsulation material is replaced with a polymer material of polymethyl methacrylate (PMMA) type which is doped with diverse kinds of organic dyes. The performance of the n-p-p+ GaInP structure has been simulated as a function of the organic dyes. Gains achieved for the short-circuit current density and conversion efficiency are, respectively, 13.13% and 13.38%, under AM1.5G illumination spectra

Study of Thin Film Solar Cells in High Temperature Condition

AbstractIn this paper, we study the effect of temperature on the Copper Indium Gallium Selenide (CIGS) thin film solar cells using the one dimensional solar cells simulator SCAPS-1D (Solar Cell Capacitance Simulator). The dependence of the CIGS solar cells characteristics on temperature was investigated from 25°C to 70°C at intervals of 5°C. We observed an apparent degradation in the open-circuit voltage and conversion efficiency with an increase of temperature from 25°C to 70°C, accompanied with degradation in the maximum power of the cell from 18.55 mW/cm2 (25°C) to 14.941 mW/cm2 (70°C). By the using of the luminescent downshifting approach, the conversion efficiency of the CIGS solar cell was enhanced under Standard Test Conditions (STC) at 25°C and in high ambient temperatures test conditions. The coefficient of the voltage variation to temperature ΔVoc /ΔT was reduced from -2 to –1.8 (mV/°C)

Чисельне дослідження температурної залежності тонкоплівкового сонячного елемента на основі CZTS

У статті чисельно досліджений вплив температури на продуктивність тонкоплівкового сонячного елемента CZTS (Cu2ZnSnS4) за допомогою симулятора ємності сонячних елементів (SCAPS-1D). Ми оцінили температурну залежність енергетичної ширини забороненої зони (Eg) шарів сонячного елемента CZTS (ZnO, CdS та CZTS) між 300 і 350 К за формулою Варшні. Помічено тенденцію до зниження Eg із середніми коефіцієнтами звуження ширини забороненої зони близько 1,48x10 – 4, 3,61x10 – 4 та 7,37x10 – 4 еВ/К для ZnO, CdS та CZTS відповідно. Отримані результати показують, що Jsc збільшується, але Voc та FF зменшуються залежно від температури. В результаті ККД падає з 12,08 % при 300 К до 11,87 % при 350 К із зміною коефіцієнта – 0,036 %/К. Робоча температура 300 К вважається більш прийнятною для досягнення високої продуктивності та максимальної ефективності в сонячному спектрі AM 1,5 G (1000 Вт/м2).In this paper, the effect of temperature on CZTS (Cu2ZnSnS4) thin film solar cell performance has been numerically investigated using Solar Cell Capacitance Simulator (SCAPS-1D). We have evaluated the temperature dependence of the energy band gap (Eg) of CZTS solar cell layers (ZnO, CdS and CZTS) between 300 and 350 K by Varshni formula. A decreased trend of Eg has been noticed with an average band gap narrowing coefficients around 1.48 x 10 – 4, 3.61 x 10 – 4 and 7.37 x 10 – 4 eV/K for ZnO, CdS and CZTS, respectively. The obtained results reveal that Jsc increases, but Voc and FF decrease with respect to temperature. As a result, the efficiency falls from 12.08 % at 300 K to 11.87 % at 350 K with a coefficient variation of – 0.036 %/K. 300 K operating temperature is considered more appropriate to achieve high performances and get maximum efficiency under AM 1.5 G (1000 W/m2) solar spectrum