Thin-Film Tandem Organic Solar Cells With Improved Efficiency

Seeking high power conversion efficiency is always a striving pathway for many researchers to commercialize organic solar cells (OSCs). Thus, it is essential to achieve high conversion efficiency to make solar oriented devices as truly green energy resource. In this paper, we report novel tandem structures based on organic materials in which homo and hybrid schemes are utilized. The homo tandem structures involve the well-known organic materials such as P3HT: PCBM and PTB7: PCBM as top and bottom absorber layers, while the hybrid tandem structure is made by the combination of P3HT: PCBM and PTB7: PCBM, respectively. Due to different absorption coefficients, simulation results indicate that the hybrid tandem structure exhibit large values for current density
$J_{sc}=22.60mA/cm^{2}$
, open circuit voltage
$V_{oc}= 0.85V$
, fill factor
$FF=68.21{\%}$
, and efficiency
$\eta =13.96{\%}$
, compared to homo tandem cell and proves to be more efficient and highly stable towards high temperatures, which indicates that the proposed structure is more suitable for practical applications.