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

对于宽禁带半导体(带隙大于约2 eV)来说，一个长期存在的问题是如何获得良好的双极导电性，以及由此产生的获得良好(有效)p-n结的问题。这个问题在II-VI材料中尤其严重，否则它们具有许多理想的性能。最近的工作表明，最基本的困难在于浅掺杂的溶解性很差。因此，通常需要非平衡杂质掺入。考虑到它的快速热猝灭和光解掺杂能力，我们建议使用激光处理。将检查这种处理是否能够在仅使用单一(初级)掺杂剂的情况下提供足够的导电性，或者是否采用新建议的程序，将这种初级掺杂剂和(移动)补偿物种两者联合并入，并随后去除后者，将是必需的。我们计划将重点放在ZnSe上，但也可能在Cd上做一些工作，以获得导电良好的p型，可重复性的。这是以前从未实现过的。好的p型将导致好的p-n结，因为好的n型是可用的，以及由此产生的器件，如绿色和更高光谱范围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.