Optimization of InP / Si heteroepitaxial growth conditions using organometallic vapor phase epitaxy
1989; Elsevier BV; Volume: 96; Issue: 2 Linguagem: Inglês
10.1016/0022-0248(89)90535-6
ISSN1873-5002
AutoresAkio Yamamoto, N. Uchida, Masafumi Yamaguchi,
Tópico(s)Nanowire Synthesis and Applications
ResumoAbstract Heteroepitaxial growth of InP on Si by organometallic vapor phase epitaxy has been studied. The two-step growth method is employed to grow InP directly on Si substrates, and the study is focused on the optimization of 1st InP layer growth conditions. Growth temperature and pH3/TMI ratio are found to be the most dominant factors for 1st InP layer growth. The optimum growth temperature is around 350°C. For an InP film grown at 350°C, lattice reconstruction and grain growth are clearly observed after the annealing near the 2nd layer growth temperature ( ∼ 600 ° C). Higher temperatures than the optimum growth temperature bring about a random nucleation and consequently discontinuous film growth. The lower limit of growth temperature results from the lack of phosphorus atoms due to the low PH3 decomposition rate. A higher PH3/TMI ratio enables us to grow a high-quality 1st InP layer at a lower temperature. By optimizing these 1st layer growth conditions, the FWHM of the X-ray rocking curve for a 2nd grown layer is reduced to 400 arcsec and the photoluminescence intensity is also increased to about 1/3 of that for a homoepitaxial InP layer. Using heteroepitaxial InP films, a thin film solar cell has been fabricated on a Si substrate. The conversion efficiency for the present cell is about 3%. Problems to be solved to increase conversion efficiency are also discussed.
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