Growth, stimulated emission, photo-and electroluminescence of InGaN/GaN EL-test heterostructures

The electroluminescence properties of InGaN/GaN electroluminescence test heterostructures grown on sapphire and silicon substrates in the temperature interval of 300-380 K were investigated as a function of current at DC and pulsed excitation. A competition between the short wavelength shift of the spectral maximum position with current increase due to filling localized states and the long wavelength shift due to heating of the recombination region was studied. An improvement in cooling conditions leads to a reduction of the long wavelength shift of the luminescence band and to an increase of the emission efficiency evidencing about a decrease of heating. Optically pumped lasing in InGaN/GaN multiple quantum well heterostructures both grown on sapphire and Si was achieved and investigated in temperature interval of 300-420 K.