Sub-bandgap photocurrent response and carrier transport properties of undoped semi-insulating LEG GaAs as a composite  

作　　者：YANGRuixia ZHAOZhengping LOUJianzhong LVMiao YANGYongjun LIULihao 

机构地区：[1]HcbeiUniversityofTechnology,Tianjin300130,China [2]HebeiSemiconductorResearchInstitute,Shijiazhuang050051,China

出　　处：《Rare Metals》2003年第3期179-184,共6页稀有金属（英文版）

基　　金：This work was financially supported by the Natural Science Foundation of Tianjin (No. 02380411);the Natural Science Foundation of Hebei Province (No. 601048)

摘　　要：Undoped (ND) semi-insulating (SI) liquid encapsulated Czochralski (LEC) GaAscrystals were investigated by photocurrent and temperature-dependent Hall measurements. It isindicated that strong nonuniformities in the distributions of impurities and defects can occur forthe NDSILEC GaAs crystal grown under a condition with strong constitutional supercooling. In suchcase, the deep level that dominates Fermi level is spacial location dependent, and the GaAs crystalbecomes a composite consisting of a large number of elementary domains with differentconductivities. The sub-bandgap photocurrent response and the carrier transport properties for thiskind of composite are quite different from those for homogeneous NDSILEC GaAs.Undoped (ND) semi-insulating (SI) liquid encapsulated Czochralski (LEC) GaAscrystals were investigated by photocurrent and temperature-dependent Hall measurements. It isindicated that strong nonuniformities in the distributions of impurities and defects can occur forthe NDSILEC GaAs crystal grown under a condition with strong constitutional supercooling. In suchcase, the deep level that dominates Fermi level is spacial location dependent, and the GaAs crystalbecomes a composite consisting of a large number of elementary domains with differentconductivities. The sub-bandgap photocurrent response and the carrier transport properties for thiskind of composite are quite different from those for homogeneous NDSILEC GaAs.

关 键 词：semiconductor material GAAS transport property hall measurement COMPOSITE constitutional supercooling photocurrent response 

分 类 号：TN304.23[电子电信—物理电子学]