ELECTRICAL-TRANSPORT PROPERTIES OF NARROW INGAAS INP QUANTUM-WELLS/

Using magnetotransport measurements we have investigated the electrica l properties oi 3 nm wide lattice-matched InGaAs/InP quantum wells gro wn by metalorganic vapour phase epitaxy. We observe a significant pers istent photoconductivity (PPC) effect even at room temperature. The en ergetic parameters of the deep level which we believe to be connected with the PPC have been determined from the variation with photon energ y and from the temperature-dependent relaxation. The PPC permits the s tudy of transport parameters as a function of the electron density. in this way, the density dependences of the in-plane effective mass and oi the ratio oi quantum to classical scattering times have been derive d from Shubnikov-de Haas oscillations. The low-field Hall effect measu rements yield peculiar anomalies in the mobility versus density curves at 77 K when evaluated on the basis of a one-band model. We show that these anomalies are caused by a second channel which can be filled wi th a limited number oi carriers.