Electrical and optical properties of InP grown at different cracking temperature and V/III ratio using a valve phosphorous cracker cell

Abstract

We report the molecular beam epitaxial (MBE) growth of epitaxial InP using a valve phosphorous cracker cell at a range of cracking zone temperature ( T cr=875–950°C) and V/III flux ratio (V/III=1.2–9.3). The as-grown epitaxial InP on InP(1 0 0) substrate was found to be n-type from Hall measurements. The background electron concentration and mobility exhibited a pronounced dependence on the cracking zone temperature and V/III flux ratio. Using a cracking zone temperature of 850°C, the highest 77 K electron mobility of 25 500 cm 2/V s was achieved at a V/III ratio of 2.3 at a substrate temperature ( T s) of 480°C. The corresponding background electron concentration was 5.65×10 15 cm −3. The photoluminescence (PL) spectra showed two prominent peaks at 1.384 and 1.415 eV, with the intensity of the low-energy peak becoming stronger at higher cracking zone temperatures. The PL full-width at half-maximum (FWHM) showed a significant reduction as the V/III ratio was lowered, indicating an improvement in the optical quality of the samples. The lowest PL FWHM achieved was 6.3 meV.