실리콘계 태양전지 제조과정에서 발생하는 불량품에서 실리콘웨이퍼를 회수하는 연구를 수행하였다. 상온(25 ℃)에서 인산용액 농도, 산성불화암모늄 농도, 킬레이트제 종류 및 농도를 변화시키면서 폐태양전지의 반사방지막 및 N층의 제거 효율을 조사하였다. 10 wt% 인산, 2.0 wt% 산성불화암모늄, 1.5 wt% Hydantoin 사용 시 제거 효율이 가장 우수 하였다. 인산농도가 증가할수록 미세입자의 표면전위가 (+)로 변하여 정전기적 인력에 의해 실리콘웨이퍼 표면에 재흡착하여 표면처리 전보다 두께가 두꺼워졌으며, 표면의 오염도도 증가하였다. 인산-산성불화암모늄-킬레이트제 용액에 의한 표면처리방법은 모든 공정이 상온에서 수행되며, 공정이 단순하고, 폐수 발생량이 적고, 표면제거 효율이 우수한 방법으로 폐 태양전지의 재활용 및 기존 RCA 세정법의 대안으로 가능성이 매우 클 것으로 판단되었다.

Recovery method of silicon wafer from defective products generated from manufacturing process of silicon solar cells was studied. The removal effect of the N layer and antireflection coating(ARC) of the waste solar cell were investigated at room temperature (25 oC) by variation of concentration of H3PO4, NH4HF2, and concentration and types of chelating agent. Removal efficiency was the best in the conditions; 10 wt% H3PO4 2.0 wt% NH4HF2, 1.5 wt% Hydantoin. Increasing the concentration of H3PO4, the surface contamination degree was increased and the thickness of the silicon wafe became thicker than the thickness before surface treatment because of re-adsorption on the silicon wafer surface by electrostatic attraction of the fine particles changed to (+). The etching method by mixed solution of H3PO4-NH4HF2-chelating agents was expected to be great as an alternative to conventional RCA cleaning methods and as the recycle method of waste solar cells, because all processes are performed at room temperature, the process is simple, and less wastewater, the removal efficiency of the surface of the solar cell was excellent.

Silicon Wafer Solar Cell Chelating Agent H3PO4 NH4HF

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