We demonstrate a new solution-processed electron transport layer (ETL), zinc oxide doped with cesium carbonate (ZnO:Cs2CO3), for achieving organic photovoltaics (OPVs) with good operational stability at ambient air. An OPV employing the ZnO:Cs2CO3 ETL exhibits a fill factor of 62%, an open circuit voltage of 0.90 V, and a short circuit current density of −6.14 mA/cm2 along with 3.43% power conversion efficiency. The device demonstrated air stability for a period over 4 weeks. In addition, we also studied the device structure dependence on the performance of organic photovoltaics. Thus, we conclude that ZnO:Cs2CO3 ETL could be employed in a suitable architecture to achieve high-performance OPV.

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In this letter, we report on the performance of conventional bulk heterojunction organic solar cell (OSC) incorporating a solution-processed zinc oxide (ZnO) spin coated on the photoactive layer regioregular poly(3-hexylthiophene) : indene-C 60 bis adduct. We show a significant improvement in short-circuit current density (J sc ) upon an introduction of ZnO, and this is further evidenced by the reduction of J sc leading to a lower PCE in the device without the presence of ZnO. Furthermore, we also examined the "photomask" on the performance of ZnO-based device yielding a decrease in both J sc and open-circuit voltage V oc (of about 13.42% and 0.73%, respectively) but an increase in filling factor. Results demonstrate that ZnO plays an important role in the improvement of OSCs' performance.

In this paper, we investigated film profile and device performance in pixel of 80ppi, 144ppi and 200ppi with 2nd harmonic structure which had thicker HIL and HTL. Pile‐up phenomena depended on ink formulation and pixel size and target film thickness. The excessive pile‐up was occurred in smaller pixel with same ink. Profiles were improved with changing the first layer ink that it had suppressed pile‐up in 200ppi size pixel. Device performance was also achieved in 200ppi size pixel compared with 80ppi size pixel device.

We have studied the effect of hole injection layers (HILs) on the performance of phosphorescent green organic light-emitting diodes (OLEDs). The PEDOT:PSS and other new PEDOT-based materials of HIL 1.3N and HIL 3.3N were used as HILs. The OLED with HIL 1.3N, having the work function of 6.08 eV, exhibits low driving voltage and high efficiency because of the improved hole injection. The position of emission zone, studied by analyzing the electroluminescence spectra, is found to be at the center of the emission layer (EML), while the emission zone is near the interface for the OLEDs with PEDOT:PSS and HIL 3.3N. This is due to the improved charge carrier balance within the EML caused by the efficient HIL of HIL 1.3N.