Efficient Method of Fabricating Polymeric Solar Cells in Multilayered Configuration Using Electrospray SAID KARIM SHAH 1,4 and ROBERTO GUNNELLA 2,3 1.—Department of Physics, Abdul Wali Khan University Mardan, Mardan, Khyber Pukhtunkhwa 23200, Pakistan. 2.—School of Science and Technology, Camerino University, Via Madonna delle Carceri, 62032 Camerino (MC), Italy. 3.—INFN-Sez. di Perugia, Perugia, Italy. 4.—e-mail: saidkarim@awkum.edu.pk Electrospray deposition (ESD) for the fabrication of multilayered (ML) bulk heterojunction polymeric solar cells via direct/inverted configurations was investigated. The active layer heterojunction (P3HT/PCBM) is deposited both in single and multilayered architectures. In ML configuration, the P3HT/ PCBM blend film is sandwiched between thin donor (P3HT) and acceptor (PCBM) layers. In ZnO-based inverted solar cells, ZnO film synthesized by sol–gel process was deposited on ITO substrate using spin coatinng. Solar cells were fabricated via ESD and spin coating and the device’s performance parameters were compared. Higher efficiency was obtained in the case of (ML) ESD device (direct structure). Post thermal treatment showed that ESD de- vices exhibit a power conversion efficiency (PCE) of 1.85% ML and 1.64% SL in direct structure while in the case of inverted structure PCEs of 1.30% ML and 0.82% SL were obtained as compared to 1.64% from the spin coated device at 120°C. The ML ESD devices have shown an overall efficiency enhancement of 13% (direct) and 58% (inverted) over the single layer (SL) ESD devices. The enhanced performance in ML devices is because there is a spatially uninter- rupted pathway to the charge carrier transport towards their respective electrodes. Key words: Polymeric solar cells, electrospray deposition, multilayered films, J–V characteristics, ZnO based Inverted organic solar cells INTRODUCTION Compared to conventional solar cell technology, polymeric solar cells (PSCs) provide an excellent opportunity for producing cheap electricity from the sun with relatively low-cost production at low processing temperatures on flexible substrates. Improvement in device efficiency, while utilizing efficient photoactive materials, has reached more than 10%. 1 However, PSC device performance is limited by poor exciton dissociation, charge carrier transport, high rates of exciton recombination and low charge carrier mobility in organic semiconductor materials. 2,3 Also, the life-time sta- bility issues of PSCs are still to be addressed. In common architecture of polymeric solar cells (PSCs), solution processed electron donor materials (P3HT) and electron acceptor materials (PCBM) are exploited for fabricating high performance solar cells. 4,5 Besides donor/acceptor materials, there is a poly(3,4-ethylenedioxythiophene):polystyrene sul- fonic acid (PEDOT:PSS) 6 buffer layer and low work function metals such as Ca/Al 4 that are used as an electron-blocking layer and an electron-collecting electrode, respectively, in the direct structure of polymeric solar cells (PSCs). However, PEDOT:PSS and low work function metals are not stable in ambient condition. 7 Therefore, to avoid these mate- rials, polymeric solar cells (PSC), in combination with high work function metals such as gold or (Received August 27, 2019; accepted November 26, 2019) Journal of ELECTRONIC MATERIALS https://doi.org/10.1007/s11664-019-07866-4 Ó 2019 The Minerals, Metals & Materials Society