PHOTOLUMINESCENCE LINESHAPE OF NARROW N-TYPE MODULATION-DOPED QUANTUM-WELLS

Photoluminescence experiments on modulation-doped single quantum wells yield a complex lineshape. A careful analysis of the spectra allows a separation of wavevector conserving and non-conserving transitions. Temperature-dependent measurements show that direct transitions dominate for higher temperatures. From this analysis we conclude that at low excitation power most of the photogenerated carriers relax to the bottom of the subbands and can be described by a temperature as low as the lattice temperature. The quantitative analysis of the lineshape allows a precise determination of all relevant parameters of the carrier system like effective masses, Fermi energy, carrier concentration in the quantum well and electron and hole temperatures.