Characterization of undoped and silicon-doped InGaN/GaN single quantum wells

We investigated the influence of doping and InGaN layer thickness on the em ission wavelength and full width at half maximum (FWHM) of InGaN/GaN single quantum wells (SQW) of thicknesses between 1 nm and 5; nm by temperature a nd intensity resolved photoluminescence (PL). The crystalline quality of th e GaN claddings was assessed by low temperature FL. The emission energy of 5 nm Si doped SQW could be tuned from 3.24 eV to 2.98 eV by reducing the de position temperature. An increase of piezoelectric (PE) field screening wit h increasing deposition temperature is attributed to an increase of the SiH 4 decomposition efficiency. Piezoelectric (PE) fields between 0.5 MV/cm and 1.2 MV/cm in undoped structures of varying SQW thicknesses were calculated . Two activation energies of 15 meV and 46 meV of the SQW emission could be observed in temperature resolved measurements. The higher value was assign ed to the confined exciton binding energy, whereas the activation energy of 15 meV is probably due to a decrease in carrier supply from the absorption zone in the GaN cladding into the SQW.