The photoassisted MOVPE growth of ZnSSe using tertiary-butylmercaptan |
| |
Authors: | D W Parent A Rodriguez P Li X G Zhang G Zhao J E Ayers F C Jain |
| |
Affiliation: | (1) Electrical Engineering Department, Presently at San Jose State University, 95192-0084 San Jose, CA;(2) Electrical and Computer Engineering Department, University of Connecticut, 06269-2157 Storrs, CT |
| |
Abstract: | We have conducted a study of the compositional control of epitaxial ZnSySe1-y grown by photoassisted metal organic vapor phase epitaxy (MOVPE) (250 torr, 340°C, UV=14 mW/cm2) on GaAs (100) substrates. We have achieved lattice matched ZnSSe films on GaAs substrates using photoassisted growth using
dimethylzinc (DMZn), dimethylselenide (DMSe), and tertiary-butylmercaptan (t-BuSH) as precursors. In addition, we have obtained
sulfur compositions (y), ranging from 0.023 to unity (ZnS). The growth rate of the ZnS was 1 μm/h, which was previously unattainable
by our group using diethylsulfur. The closely lattice matched sample (y=0.07 as determined by high resolution x-ray diffraction)
showed a near band edge peak intensity (NBE) to deep level emission intensity (DLE) ratio of 77 to 1, as determined by room
temperature photoluminescence measurements. We have examined the sulfur incorporation as a function of source mole fractions,
UV intensity, and growth temperature and found that optimized growth conditions (optimized for range of compositions possible,
and NBE/DLE ratio) are XDMZn=1.5 × 10−4, XDMSe=3×10−4, UV=14 mW/cm2, growth temperature=340°C. XDMZn and XDMSe are the mole fractions of DMZn and DMSe, respectively. We have found the growth rate to be 1 μm/h for y=0.023 to 0.24 for
these optimized conditions. It was found that to achieve sulfur compositions of less than 0.9, the t-BuSH mole fractions had
to be kept low. Higher UV intensities increased the incorporation of selenium, while also lowering the material quality (NBE/DLE
ratios). We have shown that the optical material qualities of ZnSSe films grown with t-BuSH are much better than ZnSSe films
grown with DES. |
| |
Keywords: | ZnSSe tertiary-butylmercaptan photoassisted MOVPE |
本文献已被 SpringerLink 等数据库收录! |
|