Non-uniform photocurrent transport and tunneling resonances in composite InGaAs/AlGaAs and GaAs/AlGaAs quantum wells

Abstract

Yertical tunneling transport o/photo-generoted carriers in U composite system incorporated with different @pes o/multiple-quont~m-n~~lls is experimentally investigated uf I S -300 K by photocurmi (PC) response measurements. In PC spectra of this novel siructure, pseudo-negative peaks are observed at exciton resononce wovelengihs. The negative peaks are definitely observed under low/ield and low remperature conditions. When ihe applied reverse bios is increased. howevec the dip depth instantaneously becomes to be flattened at the bios volroge o/r,.r* resononce ond the spectrol line-shape persisrs to be the same/oor further incremes o/ the reverse bias. These results of preudo-negative PC peaks w e n,eN explained by shodowing effects on the number of absorbed photons and by assuming rhe dominonce o/electron transport (IS orixins ofthe PC spectral feorum