Investigation of Cu(In,Ga)Se 2 absorber by time-resolved photoluminescence for improvement of its photovoltaic performance

Time-resolved photoluminescence on double graded Cu(In,Ga)Se2 – Impact of front surface recombination and its temperature dependence

“…Fitting the simulated PL decay times without a temperature-dependent B (solid lines, full symbols) and for small S front ¼ 10 2 cms À1 using Eqn. (2) results in an exponent of a , 1:4: The difference compared to the value used for the simulations (a = 1.5) is due to a contribution of radiative recombination. Fitting the temperature dependence in the case of a high value for S front results in a significant higher exponent a of 2.89 and 4.05 for a mobility of 10 and 50 cm 2 V À1 s À1 , respectively.…”

“…To extract the parameter a for the temperature dependence, only data points acquired from a stable sample quality (black crosses) have been used for the fitting with Eqn. (2). The fitted values are τ 0;nonrad ¼ 253 ns and a ¼ 2:1.…”

“…Time-resolved photoluminescence (TRPL) is generally applied to measure the minority carrier lifetime of Cu(In,Ga)Se 2 (CIGS)-based p-type semiconducting absorbers and a good correlation to device efficiency is observed [1][2][3][4][5]. However, experimental evidence has been presented that trapping of minority charge carriers may impact these measured lifetimes, which results in measured effective lifetimes larger than the bulk lifetime [6,7].…”

Influence of conduction band minimum difference between transparent conductive oxide and absorber on photovoltaic performance of thin-film solar cell

“…We have recently reported the fabrication of CIGS solar cell on flexible stainless steel substrate with conversion efficiency of above 16% without anti-reflective layer by the variation of band gap energy of CIGS absorber to optimize the CBO of the buffer/absorber interface; however, the carrier recombination near the interface was still observed. 14,15) In this work, in order to further increase cell efficiency, it is considered that the E C difference between TCO layer and the absorber, named ¦E C-TA , should be scrutinized. Therefore, it is intriguing to investigate the influence of the ¦E C-TA on photovoltaic performance as the useful knowledge for designing new material combination of buffer, absorber and TCO for high cell performance.…”

Quantum funneling in blended multi-band gap core/shell colloidal quantum dot solar cells

“…Further, increased PL lifetime has been shown to correlate with better material quality and device performance in other material systems. [30][31][32][33] The current-voltage and external quantum efficiency (EQE) of both blends forming heterojunctions with ZnO are shown in Figures 1(c) and 1(d), respectively. For the purpose of this study, we utilized a 200 nm thick active layer and the power conversion efficiency of both devices is poor, reaching 2.4% for the core blend and 2.1% for the core/shell blend.…”