Ag, Ti dual-cation substitution in Cu₂ZnSn(S,Se)₄ induced growth promotion and defect suppression for high-efficiency solar cells

Abstract

The existence of various detrimental defects inside the absorber layer is a major obstacle limiting the performance of kesterite Cu2ZnSn(S,Se)4 (CZTSSe) thin-film solar cells. Cationic substitution is a viable strategy...

Grain Growth Mechanism of CZTSSe Films Controlled by the Evaporation Area of Se

“…[10] Despite this, the efficiency of solutionprocessed Cu 2 ZnSn(S, Se) 4 solar cells still remains much lower than the detailed balance limiting efficiency of 32%, which is hindered by the severe nonradiative recombination and large Voc def resulting from the imperfect crystal quality. [11][12][13][14][15] As the most important process affecting the crystallinity of thin CZTSSe films, selenization needs to be further studied. In general, solid Se particles are widely used as Se source for the postselenization of CZTSSe because of the low toxicity and relatively higher safety.…”

Tailoring residual stress of flexible Cu2ZnSn(S,Se)4 solar cells by Ga doping for high mechanical endurance

“…We attribute the phenomenon of increased V oc (decreased V oc deficit) to the relief of band tail state and electrostatic potential fluctuation which originates from defects (Cu Zn , Sn Zn and V Cu ) after Ga doping. 32,33 Detailed calculation and demonstration of the electrostatic potential fluctuation will be systematically discussed below. However, excessive Ga doping with 0.42 mol L À1 will slightly weaken the performance of the solar cell, exhibiting a decreased PCE of 4.61%.…”

Progress and prospectives of solution-processed kesterite absorbers for photovoltaic applications

“…30 In contrast, DMSO-based processes require selenization, achieving a record efficiency of 13.0% (certified by NREL). 24 In addition, the other four solvent systems achieve the device efficiency of CZTSSe in the range of 11–13%, namely amine–thiol-based devices: 12.54% (Wu's group), 65 TU/DMF-based devices: 12.25% (Zhang's group), 117 EGME-based devices: 12.73% (Su's group), 139 and TGA-based devices: 12.8% (Meng's group, certified efficiency). 146 Solution deposition techniques demonstrate their ability to create controllable, dense and high-quality kesterite absorbers for photovoltaic applications, especially DMSO and TGA solvents.…”

“…133 Subsequently, Chen et al used the Ag, Ti dual-cation substitution to improve the device efficiency up to 12.73%. 139 In addition, Liang et al also obtained high-quality CZTSSe films by optimizing the ratio of Sn 4+ /Sn 2+ in the CZTSSe precursor solution (the ratio of Sn 4+ /Sn 2+ = 1 : 1) (Fig. 8f), which reduces the concentration of deep defects, fortunately, achieving efficiency of over 11%.…”