衬底温度对共蒸发制备GaSb多晶薄膜性质的影响

Effect of Substrate Temperatures on the Properties of GaSb Polycrystalline Films by Co-evaporation

采用共蒸发的方法在玻璃衬底上制备出GaSb多晶薄膜材料。研究了薄膜生长速率与衬底温度、Ga源温度和Sb源温度的关系。通过XRD、UV-Vis、Hall效应和AFM等测试方法,研究了衬底温度对于GaSb薄膜的结构特性、光电性质以及表面形貌的影响。GaSb多晶薄膜具有(111)择优取向,薄膜的吸收系数达到105cm-1,晶粒尺寸随衬底温度升高逐渐增大;衬底温度为540℃时,薄膜的迁移率达到127 cm2/V.s,空穴浓度为3×1017 cm-3。

GaSb polycrystalline thin films were prepared on glass substrates by co-evaporation method.The relationship between the film growth rate and substrate temperature,Ga source temperature,and Sb source temperature were studied.The effect of substrate temperatures（Tsub） on the structural characteristics,optoelectronic properties and surface morphology of GaSb films were studied by XRD,UV-Vis,Hall and AFM.The absorption coefficient of GaSb films is of the order of 105 cm-1.The thin films have preferential orientation of the（111） direction.The grain size increased as the substrate temperature increasing.The hole concentration of polycrystalline GaSb shows a degrading trend with increasing substrate temperature.When Tsub is up to 540 ℃ the hole concentration is 3×1017cm-3 and the hole mobility is 127 cm2/V·s.The surface roughness of GaSb film from AFM image increased with the higher substrate temperature.