Photoelectronic processes in HgGaInS4 have been studied by photoconduc
tivity, thermally stimulated conductivity and photoluminescence. An ex
ponential distribution of traps with a slope of 23 meV\decade as well
as a further electron trap system with an activation energy of 70 meV
have been localized below the bottom of the conduction band. Radiative
electron transitions are shown to occur mainly from exponentially dis
tributed traps to an acceptor level characterized by an activation ene
rgy of 220 meV. (C) 1997 Elsevier Science Ltd. All rights reserved.