Molecular beam epitaxial growth of InP using a valved phosphorus cracker cell: optimization of electrical, optical and surface morphology characteristics

We report the molecular beam epitaxial (MBE) growth of epitaxial InP using a valved phosphorous cracker cell at a range of cracking zone temperature (T_cr=875°C to 950°C), V/III flux ratio (V/III=1.2 to 9.3) and substrate temperature (T_s=360°C to 500°C). The as-grown epitaxial InP on InP (100) 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, V/III flux ratio and substrate temperature. Using a cracking zone temperature of 850°C, the highest 77 K electron mobility of 40900 cm²/Vs was achieved at a V/III ratio of 2.3 at substrate temperature (T_s) of 440°C. The corresponding background electron concentration was 1.74×10¹⁵ cm^-3. The photoluminescence (PL) spectra showed two prominent peaks at 1.384 eV and 1.415 eV, with the intensity of the low energy peak becoming stronger at higher cracking zone temperatures. The lowest PL FWHM achieved at 5 K was 5.2 meV