Catalyst-free ZnO on porous silicon grown by using vapor phase transport

Zinc oxide (ZnO) was grown on porous silicon (PS) by using vapor phase transport without a metal catalyst or seed layer. The structural and the optical properties of PS and of ZnO grown on PS were investigated using atomic force microscopy, scanning electron microscopy, X-ray diffraction, and photoluminescence. The residual stress of ZnO grown on PS could be relaxed and its structural and optical properties were improved with the introduction of a PS template as a substrate. In addition, the position of the UV emission peak for ZnO grown on PS was blue-shifted with increasing temperature. The coupling strength between excitons and LO phonons in ZnO grown on PS decreased with increasing temperature.