Carrier dynamics in amorphous semiconductor superstructures

本文讨论了a-Si：H/a-Si&lt；1-x&gt；用辉光放电方法制备了Cx：H(x=0.2，0.5和0.8)超薄多层膜，通过对11~510A范围内红外吸收光谱的分析，确定了氢原子在势垒层中的掺入方式，氢原子以Si-H_2二氢键的形式进入势垒层，形成Si-H单氢键。甚至高达。100A时，Si-H_2二氢键占主导地位，而不是Si-H一氢键，并研究了多层膜的输运机制。在具有p型势垒层的a-Si：H/a-Si_&lt；0.2&gt；C_&lt；0.8&gt；：H多层膜中，肖特基使命电导首先占主导地位，然后随着外加电压的增加，观察到Fowler-Nordheim电导。对于p型势垒层，在最佳掺杂条件下，得到了室温隧穿电流。

In this paper, we discuss microscopic structures and electrical properties of the a-Si : H/a-Si_<1-x>C_x : H (x=0.2, 0.5 and 0.8) ultra-thin multilayers fabricated by a glow discharge method.The scheme of hydrogen incorporation in the well layer was determined by the analysis of infrared absorption measurements over the range of the well-layer thickness from 11 to 510 A. Hydrogen atoms are incorporated into the well layer in the form of Si-H_2 dihydride bonds up to a well-layer thickness of 40 A, and then Si-H monohydride bonds are formed. Even up to. 100 A, the Si-H_2 dihydride bonds are dominant rather than the Si-H monohydride bonds.The transport mechanism across the multilayers has been investigated. In a-Si : H/a-Si_<0.2>C_<0.8> : H multilayers with p-type well layers, Schottky mission conduction is dominant at first and then the Fowler-Nordheim conduction is observed with increasing applied voltage. For p-type well layers, room-temperature tunneling currents is demonstrated on an optimum condition for the doping level in the well layer.