In order to protect the solar panel against reverse biasing, bypass Schottky diodes are usually connected in parallel with a string of cells which makes the circuit more complex and costly. This study presents a novel thin-film crystalline silicon device design using physics-based TCAD simulations. In our proposed solar cell, a P + reverse conducting layer is introduced to form an N ++ /P + /P structure. The novel device structure provides two different functions depending on the type of applied bias. It operates as an efficient solar cell when operating at forward biasing while it acts as a backward diode when reverse biased. Therefore, such a proposed device is self-protected against the reverse current. Also, it can reduce circuit complexity and manufacturing cost.