화학공학소재연구정보센터
Solar Energy Materials and Solar Cells, Vol.172, 55-58, 2017
Recombination-free reactive ion etch for high efficiency silicon solar cells
Carrier lifetime degradation of reactive ion etch-processed silicon samples are investigated. Two types of carrier recombination: reversible and irreversible degradations induced by reactive ion etching (RIE) are identified. Irreversible carrier recombination is due to surface damage created by the RIE process that propagates a few microns deep into the silicon substrate. Reversible carrier recombination, on the other hand, is found to be caused by radiation damage when RIE etches only into the silicon oxide, and nitrogen annealing can restore the degraded carrier lifetime. A recombination-free RIE process is then developed in combination with a passivation stack consisting of silicon dioxide and silicon nitride layers. This improved RIE process is applied to the development of high efficiency silicon solar cells resulting in a conversion efficiency exceeding 24%.