Study of ZnS epitaxial layer by triple co-doping method

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16560286
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Kochi University of Technology
• Principal Investigator: KISHIMOTO Seiichi Kochi University of Technology, 総合研究所, 助教授 (90177816)
• Co-Investigator(Kenkyū-buntansha): YAMAMOTO Tetsuya Kochi University of Technology, 工学部, 教授 (30320120)
• Project Period (FY): 2004 – 2005
• Keywords: vapor phase epitaxy / zinc sulfide / Hall effect measurement / doping / co-doping / epitaxial growth / エピタキシャル成長

Research Abstract

In order to realize the blue-light-emitting devices, we have investigated the influence of systematically varying of temperature of In source in the range from 550 to 800℃ on N incorporation, microstructures and electrical properties of triple-codoped ZnS thin films. A series of vapor-phase epitaxial ZnS : (Ag,In, and N) films were prepared on semi-insulating GaAs (100) substrates with H_2+NH_3 gas flow. The amount of NH_3 flow varied from 100 to 500 ccm. The Ag source temperature was kept at 950℃.
On the basis of the analysis of N profiles obtained by SIMS measurements, an increase in N concentrations with increasing an incorporation of In acceptors and In-reactive donors was deduced. Hall measurements using the Van der Pauws method at room temperature revealed that free hole concentrations and Hall mobility range (1.31-8.76)×10^<18> cm^<-3> and 58.4-80.5 cm^2/Vs, respectively.
It was established that the growth conditions with the amount of NH_3 flow varying from 200 to 300 ccm and In source about 650 to 750℃ in temperature are very effective for the realization of good p-type ZnS : (Ag,In,N) with high Hall mobility.