OPTICAL CHARACTERIZATION OF REAL-SPACE HOT-ELECTRON TRANSFER IN A STRAINED GAAS IN0.2GA0.8AS/GAAS QUANTUM-WELL HETEROSTRUCTURE/

Real-space transfer (RST) light-emitting transistors are implemented w ith a strained GaAs/InGaAs/ GaAs quantum well heterostructure fabricat ed on GaAs substrates. The device energy band diagrams are simulated b y using the MEDICI program. Two optical measurements, electroluminesce nce (EL) and photocurrent, are performed to characterize the RST light -emitting transistors. The RST of hot electrons into the active region is measured by EL at 77 K. The light emitted from the RST device is d etected by a separate photodetector and the photocurrent is found to b e consistent with the RST current-voltage (I-C - V-D) characteristics. The 77 K EL emission peak wavelength is about 9000 Angstrom. The EL s pectra confirm that the emission is dominated by emission from the GaA s/InGaAs/GaAs quantum well. At V-D=0 V, the EL emission intensity due to hole leakage current is about 2 orders of magnitude lower than that of the electron leakage current. (C) 1997 American Institute of Physi cs.