【摘要】 测量夹心结构α-Si∶H膜的瞬态响应谱时,发现无论是在低的正向偏压还是在低的反向偏压下,起始部分都出现不正常的尖形脉冲,它的幅度随光波长的增长而减小。零场瞬态谱的研究表明,这种不正常的非传输部分来源于结区,它的升降特点决定于光照时的空间电荷限制光电流。从光电流幅值与光吸收系数的关系式,我们发展了一种确定光学隙的方法。更多还原

【Abstract】 Transient photoresponse spectra in α-Si: H film with sandwich structure are mea-sured. It is found that at the starting part of these curves anomalous pulse appears under either a small forward bias or a small reverse one. The pulse amplitude decreases when the light wavelength increases. Analysis of the transient response spectra without bias, showed that this anomalous non-transport component originates from the barrier region. Its rise or deeay characteristic is determined by space-charge-limited photocur-rents. With the relation between its amplitude and optical absorption, we developed a method to obtain uptical band gap of the films studied.更多还原