DUKSAN Neolux (South Korea)

Inverted organic solar cells (OSCs) have been fabricated with conventional Sn-doped indium oxide (ITO) and amorphous indium gallium zinc oxide (a-IGZO)/Ag/a-IGZO (39 nm/19 nm/39 nm) (a-IAI) electrodes and their electrical characteristics characterized. The ITO and optimized a-IAI electrodes showed high transmittance of 96% and 88% at 500 nm, respectively. The carrier concentration and sheet resistance of the ITO and a-IAI films were 8.46 × 1020 cm−3 and 7.96 × 1021 cm−3 and 14.18 Ω/sq and 4.24 Ω/sq, respectively. Electron transport layer (ETL)-free OSCs with the a-IAI electrode exhibited power conversion efficiency (PCE) of 2.66%, similar to that of ZnO ETL-based OSCs with ITO electrode (3.27%). However, the ETL-free OSCs with the a-IAI electrode showed much higher PCE than the ETL-free OSCs with the ITO electrode (0.84%). Ultraviolet photoelectron spectroscopy results showed that the work function of the a-IAI electrode was 4.15 eV. This improved performance was attributed to the various roles of the a-IAI electrode, e.g., as an effective ETL and a hole blocking layer.

We investigated the effect of ZnO layer thickness on the optical and electrical properties of ZnO/Ag/ZnO multilayer films deposited on glass substrates. The transmission window became wider and shifted toward the lower energy side with increasing ZnO thickness. The ZnO/Ag/ZnO (40 nm/18.8 nm/40 nm) multilayer sample showed transmittance of ~96% at 550nm. As the ZnO thickness was increased from 8 nm to 80 nm, the carrier concentration gradually decreased from 1.74 × 1022 cm−3 to 4.33 × 1021 cm−3, while the charge mobility varied from 23.8 cm2/V-s to 24.8 cm2/V-s. With increasing ZnO thickness, the samples exhibited similar sheet resistances of 3.6 Ω/sq to 3.9 Ω/sq, but the resistivity increased by a factor of 4.58. The samples showed smooth surfaces with root-mean-square roughness in the range of 0.47 nm to 0.94 nm. Haacke’s figure of merit (FOM) was calculated for all the samples; the ZnO (40 nm)/Ag (18.8 nm)/ZnO (40 nm) multilayer produced the highest FOM of 148.9 × 10−3 Ω−1.

Abstract

We synthesize Si foam particles via magnesiothermic reduction of silica foam. Three effective strategies, like control of the calcination conditions of silica foam, introduction of a heat scavenger and doping of electrically conductive layers, lead to significant improvement of the electrochemical properties of the Si foam anodes.

The efficiency improvement of fluorescent blue organic light-emitting diodes were investigated by inserting buffer layer. The OLED device using several buffer materials which have different HOMO and LUMO energy level were evaluated. The inserted buffer layer could control the effective hole injection and electron blocking, which leaded to remarkable high efficiency performance.

Abstract New green host materials (VI) are obtained by attaching the electron transporting benzimidazole moiety to the hole transporting carbazole unit.