p型α-多孔SiC的光致发光光谱研究

用UV光照射和不用UV条件下形成的p型α-PSC的PL光谱，2.35eV，2.50eV和2.70eV及3.4eV附近的发射峰已被观察到.研究了不同的制备条件下形成的p型α-PSC的PL谱的稳定性和不同的能量的光激发引起PL谱的差别.结果表明，在电化学腐蚀过程中制备条件对PSC的PL谱有很大的影响，前者在低能区有较强的光发射而后者则在高能区有较强的光发射；前者的光谱稳定性较好而后者发射光谱强度则随时间的增加而减少.对产生这些差别的原因进行了深入讨论. 关键词：

STUDY OF PHOTOLUMINESCENCE SPECTRUM IN p-TYPE α-POROUS SILICON CARBIDE

The photoluminescence (PL) spectra from p-type α-porous silicon carbides prepared under UV photo-assisted process and under dark-current condition are investigated in detail. Emission bands with peak energies of 2.35, 2.50,2.70, and 3.43 are resolved. The PL stability in time and the PL difference arising from different tuning excitation energies are studied. It is found that the PL spectra of the α-porous silicon carbide depend strongly on the preparation conditions for electrochemical etching. The PL spectrum of the sample prepared under photo-assisted process has an enhancement on the lower-energy side of the emission; on the contray, another one under dark-current condition has an enhancement at the higher energy side, and the former stability is better than the latter one, and the latter PL intensity decreases with the increase of the time in the air. The reasons about these differences are discussed.