Influence of Back Contact Annealing Temperature in the mc-Si Solar Cell Fabrication Process

The boron doped multi-crystalline silicon (mc-Si) ingots were grown using the directional solidification process. Grown ingots were converted into bricks and then to wafers. We have fabricated silicon solar cells from the multi-crystalline silicon wafers. The minority carrier lifetime of the wafers is around 15–25 µs. The effect of back contact annealing temperature has been investigated. Annealing the device at 583 0 C for 5 s gives better results. Typical open circuit voltage (V oc ) of the devices is around ~ 540-550mV. The best cell had a power conversion efficiency of ~ 9 % with a typical acceptor doping density ~ 2.35 E + 15 per cm 3 (The devices reported here do not have AR coating layer, no passivation was done and the surfaces are also not textured).