GaInP_2/GaAs/Ge级联电池隧道结的结构设计及金属有机化学汽相淀积生长研究

Metal organic chemical vapor deposition growth and structure design of tunnel junction of GaInP_2/GaAs/Ge tandem solar cells

采用国产的低压金属有机化学汽相淀积(LP MetalOrganicChemicalVaporDeposition,简写为LP MOCVD)设备,生长了GaInP2/GaAs/Ge双结级联电池隧道结,分析了隧道结结构的设计原理.利用霍耳测试仪、X射线双晶衍射仪、二次离子质谱仪,对隧道结的重掺杂和互扩散特性进行了研究.结果表明,在生长温度为600℃,H2Se流量为3mL/min及隧道结N型层掺杂剂选用Se的条件下,可得到电子浓度为5×1019cm-3;而采用自掺C(通过不断改变五族元素与三族元素之比)可得到P型载流子浓度为1017～1021cm-3的GaAs隧道结.说明该生长方法可获得电池隧道结中高掺杂水平的PN结,并且能够达到抑制掺杂杂质互扩散现象的设计要求.

The GaAs tunnel junction of GaInP_2/GaAs/Ge tandem solar cells had been obtained by a China-made low pressure LP-Metal Organic Chemical Vapor Deposition (LP-MOCVD) system. The design principle of tunnel junction is studied. The characteristic of heavy doping level of tunnel junction and diffusion each other is investigated by means of Hall technique, X ray diffraction technique and SIMS. The experiment result is that the tunnel junction of GaInP_2/GaAs/Ge of the electron concentration 5×10~19 cm^-3 and hole concentration 10~17～10~21cm^-3 of high doping level of MOCVD growth is obtained under the temperature being 600℃, the flux of H_2Se being 3 mL/min N layer doping using se and P layer doping using Carbon (by ratio of group Ⅴ/Ⅲ) condition. It is proved that by the method, the PN junction can be obtained of high doping level and doping diffusion, stopped.