钇掺杂对Cu_(2)ZnSn(S,Se)_(4)薄膜太阳电池性能的影响

Influence of yttrium doping on performance of Cu_(2)ZnSn(S,Se)_(4) based thin-film solar cell

利用溶胶-凝胶法生长出Y名义掺杂量x(=Y/(Y+Sn))为0~0.07的单一kesterite结构的Cu_(2)ZnSn(S,Se)_(4)(CZTSSe:Y)薄膜,并利用传统工艺制备出以CZTSSe:Y为吸收层的薄膜太阳电池,探讨了Y掺杂对CZTSSe:Y太阳电池光电转换效率(PCE)的影响规律和机制.研究发现:当x从0增加到0.05时,PCE从2.26%增加到5.68%;当x从0.05增加0.07时,PCE却从5.68%降低到2.90%.通过计算,阐明了光生电流密度(J_(L))、反向饱和电流密度(J_(0))、并联电导(G_(sh))和串联电阻(R_(s))随Y掺杂量的改变对开路电压(V_(oc))、短路电流密度(J_(sc))、填充因子(FF)和PCE的增加或减小的贡献程度.通过表征CZTSSe:Y薄膜的结构、晶体质量和电学性能随Y掺杂量的变化,阐述了Y掺杂对CZTSSe:Y太阳电池V_(oc)、J_(sc)、FF和PCE的影响机制.

A Yttrium(Y)doped Cu_(2)ZnSn(S,Se)_(4) films(CZTSSe:Y)with kesterite structure were grown by sol-gel technology in a nominal doping content x(=Y/(Y+Sn))of 0 to 0.07.Film solar cells with the CZTSSe:Y as absorber were fabricated by using conventional process.Influence mechanism of Y doping on power conversion efficiency(PCE)is studied.It is found that the PCE increases from 2.26%to 5.68%when the x increases from 0 to 0.05,but decreases from 5.68%to 2.90%when the x increases from 0.05 to 0.07.It is calculated on contribution degree of changes of photogenerated current density(J_(L)),reverse saturation current density(J_(0)),series resistance(R_(s))and shunt conduction(G_(sh))on increase or decrease in open-circuit voltage(V_(oc)),short-circuit current density(J_(sc)),filling factor(FF)and PCE.Influence mechanism of Y doping on V_(oc),J_(sc),J_(sc) and PCE are elaborated by characterization of change of structure,crystal quality and electrical properties of the CZTSSe:Y films.