Oxide/p-In4Se3 and n-InSe/p-In4Se3 heterostructures were prepared by t
hermal oxidation of In4Se3 and by bringing the components into optical
contact, respectively The high quality of the diodes obtained was dem
onstrated by measuring capacitance-voltage and current-voltage charact
eristics. The long-wavelength edge of the spectral response lies near
1.8 mu m. Qualitative energy-band diagrams and some photoelectric prop
erties are reported.