Abstract
In this study, we focused on two different parts: observing minority carrier lifetime of Al2O3 passivation layer and new structure of solar cell with grid-shaped electrode. The first part, we fixed annealing time with different annealing temperature, to find the best parameter value of minority carrier lifetime. The best result is Al2O3 thickness 10nm with annealing temperature 500℃ 15mins. In our experiment, we found that minority carrier lifetime would decay with time after annealing. We used C-V measurement to know that inversion voltage of Al2O3 had been displacement, and proved that the negative charge density had actually decayed. And we guessed that the decay of minority carrier lifetime of Al2O3 passivation layer was caused by hydroxide (-OH) bond by the result of FTIR measurement. The second part, we changed the shape of backside electrode to try to get lower cost and higher efficiency solar cell. In our preliminary study, the best efficiency was 16.57% with fill factor (F.F.) 77.9%.