不同激发密度下CdS晶体的光致发光和受激发射

本文主要研究在77-111K温度范围内、不同激发密度的N2激光器的337.1nm谱线激发下,激子-激子(Ex-Ex)、激子-载流子(Ex-e)的相互作用和发射一个LO声子(Ex-1LO)、两个LO声子(Ex-2LO)的自由激子的辐射复合行为.并在77K温度下观测到由Ex-Ex发射产生的受激发射.

PHOTOLUMINESCENCE AND STIMULATED EMISSION IN CdS CRYSTAL AT DIFFERENT EXCITATION DENSITY

The research work on the photoemission in CdS crystal was mostly limited in the behavior of bound exciton, excitonic molecule and exciton-exciton (Ex-Ex) interaction at rather lower temperature1-3]. Saito et al.3] studied the emission of the near-band edge in CdS within 8-65K. We have investigated exciton-carrier (Ex-e) interaction and the annihilation of a free exciton with emission of a photon and one-LO or two-LO phonons utilizing the photo luminescence (PL) and electroluminescence (EL)5]. Up to now, there has been no report on Ex-Ex interaction in CdS crystal at the temperature higher than 80K.This paper mainly studies the behavior of Ex-Ex, Ex-e,Ex-1LO and Ex-2LO interaction and the stimulated emission due to Ex-Ex interaction in CdS.The CdS crystal used in this experiment was grown by sublimation method in our laboratory.The PL spectra were measured by Model 44W spectrometer with a RCA C31034 photomultiplier at the excitation of 337.1nm line of a N2 laser in the temperature range of 77K-RT.Fig.