Eur. Phys. J. B 30, 39-43 (2002)
https://doi.org/10.1140/epjb/e2002-00355-x

Photoreflectance investigation of hydrogenated (InGa)(AsN)/GaAs heterostructures

¹ INFM-UdR Pavia, Via Bassi 6, 27100 Pavia and Dipartimento di Fisica della Università di Parma, Viale delle Scienze 7a, 43100 Parma, Italy
² INFM-Dipartimento di Fisica A. Volta, Università di Pavia, Via Bassi 6, 27100 Pavia, Italy
³ INFM-Dipartimento di Fisica, Università di Roma, Piazzale A. Moro 2, 00182 Roma, Italy
⁴ Universität Würzburg, Technische Physik, Am Hubland, 97074 Würzburg, Germany

Corresponding author: ^a geddo@fisicavolta.unipv.it

Received: 23 June 2002
Published online: 19 November 2002

Abstract

The optical response of as grown and hydrogenated In_0.32Ga_0.68AsN_y/GaAs single quantum wells (y = 0, 0.027) has been investigated from T=80 K to room temperature by photoreflectance. Three excitonic spectral features detected in the N free sample shift to lower energy in the N containing sample and back to higher energy upon H irradiation of the N containing sample. In the hydrogenated sample, a progressive change with increasing temperature of the nature of the lowest energy transition from an excitonic to a band-to-band character has been explained in terms of an increasing release of carriers from traps formed by H and N clusters. A reduction in the oscillator strength of the lowest energy transition and an increase in the binding energy of the heavy-hole exciton have been explained in terms of an increase in the electron effective mass upon N introduction into the In_xGaAs lattice.