Conditions for efficiency improvement and optimization in indium‐tin‐oxide/p‐indium‐selenide solar cells are discussed in this paper. This aim is achieved by using low‐resistivity p‐indium‐selenide and by incorporating a back‐surface‐field contact. This contact is insured by a p‐indium selenide/gold barrier whose rectifying behavior is explained through the complex impurity structure of p‐indium‐selenide. Electrical and photovoltaic properties of the cells are also reported. The efficiency parameters under AM1 simulated conditions have been improved up to 32 mA/cm2 for the short‐circuit current density, 0.58 V for the open‐circuit voltage, and 0.63 for the filling factor. As a result, solar efficiencies larger than 10% in annealed cells and 8% in unannealed ones have been attained. The limitations of these devices are discussed by investigating the dependence of electrical and efficiency parameters in function of photon flux and temperature.