The heterogeneous network (HetNet) which consists of several small cell base stations (BSs) and an overlaid macro cell BS is a promising solution to accomplish very high data rate and energy-efficient communication. The design of energy-efficient mechanisms and radio resource allocation among BSs is an important issue in HetNet. There are a variety of ON/OFF switching algorithms for BSs in the literature. However, none of these algorithms jointly consider the resource allocation problem. In this paper, we propose a hybrid interference-aware channel segregation based dynamic channel assignment (IACS-DCA) and BS sleep mode algorithm. This algorithm helps to mitigate the co-channel interference (CCI), experienced by user equipments (UEs). Simulation results show that by applying the proposed IACS-DCA approach along with a game-theory based algorithm for ON/OFF switching, higher energy- and spectral-efficiency can be achieved compared to the conventional approaches.