Study on Room Temperature Operation of PbSrS and PbEuS 3 Mum Lasers

为了获得在室温下工作的3个mum激光器，研究了PbS单晶生长、PbSrS/PbS DH和MQW激光器以及与PbS衬底匹配的PbCdSrS薄膜晶格的HWE生长。对于PbS的单晶生长，主要研究了生长对衬底棒材料的依赖性，用于生长的衬底棒材料有BaF_2（111）、SiO_2玻璃、Al_2O_3（1000）和Al_2O_3（0101^^-）。用SiO_2玻璃和Al_2O_3（0101）作为衬底棒，可获得大的单晶。对于PbSrS/Pbs DH激光器，在活性层厚度为0.5 mum时获得最高工作温度。在激光中，PbSrS包层与PbS有源层之间的晶格失配导致了PbS有源层的晶格应变。随着活性层厚度的增加，应变效应逐渐减弱，晶格失配导致界面处出现许多失配位错。对于PbSrS/PbS MQW激光器，没有观察到工作温度的升高，但观察到特征温度的升高，表明有可能提高工作温度。采用HWE生长技术对PbCdSrS晶格与PbS匹配的薄膜进行了研究，得到了质量较好的薄膜。

To obtain 3 mum lasers operating at room temperature, PbS single crystal growth, PbSrS/PbS DH and MQW lasers and HWE growth of PbCdSrS films lattice matched with the PbS substrate were studied. For single crystal growth of PbS, dependence of growth on substrate rod materials were mainly studied, Therod materials used for the growth were BaF_2 (111), SiO_2 glass, Al_2O_3(1000), and Al_2O_3(0101^^-). When SiO_2 glass and Al_2O_3 (0101) were used as the substrate rod, a large single crystal was obtained reproducibly. For PbSrS/Pbs DH laser, highest operating temperature was obtained at the active layer thickness of 0.5 mum. In the laser, lattice mismatch between PbSrS cladding layer and PbS active layer resulted in lattice strain of the PbS active layer. With increasing active layer thickness, the strain effect grad ually decreased and the lattice mismatch resulted in many misfit dislocations at the interface. For PbSrS/PbS MQW laser, increase of the operating temperature was not observed, but increase of the characteristic temperature, which shows a possibility to increase the operating temperature, was observed. PbCdSrS films lattice matched with PbS was also studied using the HWE growth technique, and good quality films were obtained.