| 초록 |
Na and K incorporation into Cu(In, Ga)Se2 (CIGS) is one of the key features for enhancement of photovoltaic conversion efficiency(PCE) in recent progresses. The exact role of K is not fully understood so far, but in many research groups reported that applying both Na and K to CIGS has beneficial effect on solar cell efficiency. In this experiment CIGS films were grown at 400°C, while Cu was supplied after (In,Ga)2Se3 film was formed. In Se-deficient condition, CIGS film growth mechanism is different from that of ordinary 3-stage CIGS deposition. Without external doping this Se-deficient CIGS solar cell have limited open circuit voltage and PCE. Upon K doping CIGS solar cell had noticeable change in recombination current. By the design of Na and K post deposition treatment procedure the effect of alkali elements doping on CIGS solar cell were investigated. |
