Phase Development and Electrical Characteristics of n-Type Semiconductive Transparent In_2O_3(ZnO)_2 Ceramics with ZnO/SnO_2 Co-Substitution

摘要

The phase development and electrical characteristics of In_2O_3(ZnO)_2 were examined when SnO_2 (Sn~(+4)) and ZnO (Zn~(+2)) in a ratio of 1:1 were simultaneously substituted for In_2O_3. When In_2O_3(ZnO)_2 was sintered it was separated into In_2O_3 and In_2O_3(ZnO)_3 phases and the co-substituent of (Zn_(0.5)Sn_(0.5)O)_(1.5) was soluble in both In_2O_3 and In_2O_3(Zn0)3. As the amount of (Zn_(0.5)Sn_(0.5)O)_(1.5) increased up to 15 at%, which is regarded as the solubility limit, both In_2O_3 and In_2O_3(ZnO)_3 phases still maintained. The grain size of the sintered body was almost invariant regardless of the amount of (Zn_(0.5)Sn_(0.5)O)_(1.5) within the solubility limit. The electron mobility was constant while the carrier concentration declined slowly, which resulted in a decrease in conductivity. When the (Zn_(0.5)Sn_(0.5)O)_(1.5) was added beyond the solubility limit, a new phase of Zn_2SnO_4 was produced, which reduced the volume fraction of the In_2O_3 and In_2O_3(ZnO)_3 phases as well as electrical conductivity.