硅中浅杂质的激光感应光电导谱

首次采用光子能量小于硅中浅受主杂质电离能的可调谐远红外激光器作为激发源,获得了硅中浅受主杂质的光电导谱.可调谐半导体远红外激光器的调谐范围为380～500cm~(-1),光子流密度约10~(18)/cm~2·sec,用双光子跃迁对光电导谱进行了解释.对于Si:Al样品,光电导谱中的双峰分别相应于2P~1和2P~2中间态的双光子共振跃迁.也观察到了双光子透明的反共振现象.

Laser-induced photoconductivity spectroscopy from shallow acceptor impurities in silicon

Using a tunable semiconductor laser in the spectral range of 380cm-1 to 500cm-1, laser-induced photoconductivity spectrum from shallow acceptor impurities in silicon was observed for the first time. The photon flux on the sample was typically 1018 per cm2-sec., and the photon energy was smaller than the ionization energy of the impurities. Two photon transition is suggested for the representation of the spectrum. Resonances in the photoconductivity spectrum are observed for the photon energies corresponding to the 2p1 and 2p2 states of Si: Al which act as intermediate states for the two photon transition. Anti-resonance due to two photon transparency is also observed.