Astronomy Detector Array Applications

作为碲化汞镉（MCT）的替代品，该计划将研究最近发明的一类由（GA,As）相关化合物制成的II型应变层超晶格的光学性质。与以前的研究相比，新概念具有优势，因为在超晶格中使用足够薄的重复层可以实现小的带隙，从而使它们具有良好的光吸收特性和良好的电输运特性，原始计算表明Ga1-xInxSb/InAs是此类应用的最佳选择。最近，与所有其他超晶格材料相比，它在10um波长处具有最高的吸收系数。为了探索这种材料体系的潜力，研究人员将采用多工艺分子束外延技术制造探测器器件结构，其中探测器层，钝化和金属化都是在原位完成的。

As an alternative to mercury-cadmium telluride (MCT), this program will investigate the optical properties of a recently invented class of type II strained-layer superlattices made of (GA,As) related compounds. The new concept has advantages compared with previous efforts in that small band-gaps may be achieved with sufficiently thin repeating layers in the superlattices so that they have good optical absorption properties and favorable electrical transport properties original calculations have indicated Ga1-xInxSb/InAs to be the best choice for such application. Very recently it has been shown to have the highest absorption coefficient at 10um wavelength compared to all other superlattice materials. To explore the potential of this material system, the investigators will fabricate the detector device structures by a multi-process molecular beam epitaxy technique in which the detector layers, passivation and metallization are all done in-situ.