Age-induced oxide on cleaved surface of layered GaSe single crystals

It is shown that a long-term keeping of a layered gallium monoselenide at room temperature results in formation of the intrinsic oxide at a cleaved surface of semiconductor. It is found that the chemical compositions of the intrinsic oxide at the surfaces of the intentionally undoped and doped samples of GaSe are different. The electrical properties of the GaSe-intrinsic oxide system are presented. It is established that intrinsic oxide films at the surface of GaSe are characterized by current instability with N-type current-voltage characteristic. The influence of relative humidity on changes of capacitance and surface resistivity of the intrinsic oxide is also discussed.