Optically enhanced semi-transparent organic solar cells through hybrid metal/nanoparticle/dielectric nanostructure

• DOI: 10.1016/j.nanoen.2015.08.014
• Publication Date: 2015-09-02T09:43:00Z
• Authors: Xingang Ren; Xinchen Li; Wallace C.H. Choy
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

Abstract Semi-transparent organic solar cells (st-OSCs) that hold high recovery of efficiency with sunlight illumination from both electrodes are of great interest in different applications. While the issues for improving the recovery of efficiency from top-illumination are very limited studied, we propose a hybrid optical nanostructure metal/nanoparticle/dielectric (M/NP/D) to achieve high recovery of efficiency. The M/NP/D nanostructure consists of high index and low-loss nanoparticles (NPs) (here we use Si NPs scatter instead of metal NPs) and index matching material (here we use Tris(8-hydroxyquinolinato) aluminum-Alq3) on ultra-thin Ag film, i.e. Ag/Si NPs/Alq3 as the top hybrid electrode of st-OSCs. Our results show that the transmission of the electrode is improved complementarily in long (due to Si NPs) as well as short wavelength regions (due to Alq3 layer) with additional synergetic improvement (due to hybrid M/NP/D nanostructure). Subsequently, the enhanced average visible transmittance (AVT) up to 32% is achieved for the proposed st-OSCs. Simultaneously, compared to the optimized control st-OSC with the bare ultra-thin Ag electrode, the power conversion efficiency (PCE) for top-illumination case is improved by about 34%, with a recovery of efficiency up to 68%. Moreover, angular dependence of short circuit current (Jsc) of st-OSCs with the hybrid electrode can be also alleviated. Consequently, the proposed transparent hybrid electrode can contribute to the emerging semi-transparent optoelectronics.