Electrical simulation of different photoactive layer thickness on organic heterojunction solar cell

Organic bulk heterojunction solar cell based on poly 3- hexylthiophene (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend as photoactive layer had been electrically simulated and analyzed at different thickness using general-purpose photovoltaic device model (GPVDM) software. Conjugate polymer P3HT acted as an electron donor, whereby PCBM acts as an electron acceptor in the device. The electrical simulation is performed at three different thicknesses of 50 nm, 100 nm, and 200 nm with P3HT/PCBM blend and hetero-layer configurations, respectively. The simulation analysis clearly demonstrated that both device configurations exhibited current-voltage (I-V) characteristics with highest short-circuit current density (Jsc) value of 2.26 mA/cm2 with P3HT/PCBM of blend configuration at 200 nm thickness. However, an open-circuit voltage (Voc) and fill factor (FF) showed a constant value, which 0.55 V and 0.72 a.u., respectively, for both device configurations. The obtained value of solar cell parameters was then analysed and compared with experimental data. This simulation work strongly reveals that different thickness of photoactive material affects the electrical performance even in different organic solar cell configurations.