Poly-silicon thin films prepared by low temperature aluminum-induced crystallization

P-type poly-Si thin films prepared by low temperature Aluminum-induced crys tallization and doping are reported. The starting material was boron-doped a-Si:H prepared by PECVD on glass substrates. Aluminum layers with differen t thicknessess were evaporated on a-Si:H surface and conventional thermal a nnealing was performed at temperatures ranging from 300 to 550 degreesC. XR D, SIMS, TEM and Hall effect measurements were carried out to characterize the annealed films. Results show that a-Si:H contacted with adequate Al cou ld be crystallized at temperature as low as 300 degreesC after annealing fo r 60 minutes. This material has high carrier concentration as well as high Hall mobility and can be used as a p-layer or seed layer for thin film poly -Si solar cells. The technique reported here is compatible with PECVD proce ss.