Study of ZnS epitaxial layer by triple co-doping method

为了实现蓝色发光器件，我们研究了在550 ~ 800℃范围内系统地改变In源温度对三共掺杂ZnS薄膜N掺杂、显微结构和电学性能的影响。采用H_2+NH_3气相流在半绝缘GaAs（100）衬底上制备了一系列气相外延ZnS: （Ag,In， N）薄膜。NH_3流量为100 ~ 500 ccm。Ag源温度保持在950℃。根据SIMS测量得到的N谱分析，推断出N浓度随着in受体和in反应供体掺入的增加而增加。利用Van der Pauws方法在室温下进行的霍尔测量结果表明，自由空穴浓度和霍尔迁移率范围分别为（1.31-8.76）×10^<18> cm^<-3>和58.4-80.5 cm^2/Vs。结果表明，在NH_3流量为200 ~ 300 ccm，In源温度为650 ~ 750℃的条件下，可以有效地制备出具有高霍尔迁移率的p型ZnS: （Ag,In，N）。

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.