Laser Processing of Wide-Gap II-VI Compounds for Improved Conductivity Control

宽带隙半导体（带隙大于2ev）长期存在的问题是获得良好的双极电导率，由此产生的问题是获得良好（有效）的p-n-函数。这个问题在II-VI类材料中尤为严重，这些材料在其他方面具有许多理想的特性。最近的工作表明，基本的困难在于浅掺杂剂的溶解度差。因此，通常需要非平衡杂质掺入。鉴于激光加工的快速热猝灭和光解掺杂能力，我们建议使用激光加工。将检查这种处理是否可以仅使用单一（主要）掺杂剂来获得足够的导电性，或者是否需要一种新建议的程序，将这种主要掺杂剂和（可移动的）补偿物质联合结合，随后去除后者。我们计划将重点放在ZnSe上，但也可能在cd上进行一些工作，并获得导电良好的p型，可重复性。这是以前从未实现过的。良好的p型会导致良好的p-n结，因为良好的n型是可用的，由此产生的器件，如绿色和更高光谱范围内的发光二极管和二极管激光器，以及更好的太阳能电池。

A long-standing problem for wide-band-gap semiconductors (band gap greater than about 2 eV) is that of obtaining good bipolar conductivity, with resultant problems of obtaining good (efficient) p-n- cunctions. This problem has been particularly severe in the II-VI materials, which otherwise have a umber of desirable properties. Recent work has shown that the basic difficulty resides in a poor solubility of shallow dopants. Consequently, non-equilibrium impurity incorporation is generally required. We propose to work with laser processing, in view of its very rapid thermal quenching and its photolytic doping capabilities. It will be checked whether such processing can give adequate conductivity with use of just a single (primary) dopant, or whether a newly suggested procedure , joint incorporation of both such a primary dopant and a (mobile) compensating species, with subsequent removal of the latter, will be required . We plan to focus on ZnSe, but with some work probably also on CdS, and obtain well - conducting p-type, reproducible. This has not been previously achieved. Good p-type would lead to good p-n junctions, since good n-type is available, and resultant devices, such as light emitting diodes and diode lasers in the green and higher spectral ranges, and better solar cells.