摘要： There is a growing need for the development of thin film flexible solar cells with improved efficiency based on the market demand. This review article helps to compare nickel oxide based thin films with other metal oxides which are used to make thin film solar cells. CdS/CdTe, CIGS and GaAs based thin film solar cells also discussed and compared their efficiencies with metal oxide based solar cells. Various processing methods used for the preparation of thin films are discussed in the literature review part and the suitable method for making thin films are proposed. The work carried out so far with the addition of dopants such as Sr, Cu, Ag, Y, Au and Li concentration in nickel oxide layer was discussed. Thin film solar cell efficiencies with and without dopants in NiO layer are compared in a detailed manner in this article. The efficiencies of doped and undoped NiO based thin film solar cells with single crystal silicon solar cells are also compared.