From a stoichiometric melt of the components using the Bridgman-Stockbarger technique the layered In2Se3 a-polytype crystals (energy band gap Eg=1.42 eV at room temperature) with the inclusions of In6Se7 (Eg(dir)= 0.64 and Eg(indir)= 0.34 eV at T= 300 K) nanocrystals are obtained. It is shown that dark current-voltage (I-V) characteristics of such samples exhibit regions of N-shaped negative differential conductivity and Z-shaped portions of intrinsic bistability, both typical for semiconductor multiple-quantumwell structures or superlattices (including disordered ones). The quenching of current in In2Se3/In6Se7 samples is observed under integral illumination (the absolute values of integral negative photosensitivity reach up to 0.18-0.23 Amps/Watt). And in “high resistivity condition” I-V characteristics of samples exhibit Ohmic behavior. It is found that photocurrent spectra of In2Se3/In6Se7 samples composed of positive (hn = 0.8 – 2.0 eV) and negative (hn = 0.71 – 0.8 eV) parts. Experimental results are interpreted using modified Stockmann model.