The demand for electricity is increasing day by day. Since electricity is the life force of modern civilization and we can get as much as we want from sun, solar cells has gained maximum attention over a short period of time. The development of conjugated alternating donor-acceptor terpolymer will give a simplistic and cost effective method to improve their light absorbing capability and tuning of energy levels. In this paper the typical current-voltage behavior, power conversion efficiency of a normal organic solar cells is compared with the recent progress of conjugated D-A terpolymers for efficient PSCs and also discussed how these photovoltaic performance get influenced by all these factors by providing useful guidelines to design new terpolymers towards high efficiency PSCs