The properties of sol–gel processed indium‐doped zinc oxide semiconductor film and its application in organic solar cells

Abstract

Indium‐doped ZnO (IZO) films with various indium contents were deposited by sol–gel process for application in organic solar cells (OSCs). X‐ray photoelectron spectroscopy (XPS) spectrum verified that indium is incorporated in the ZnO films. All films showed polycrystalline nature with a hexagonal wurtzite structure of ZnO. The resistivity of the films initially decreases yet increases again with higher doping. The lowest resistivity of 5.54 × 10−1 Ω‐cm was obtained at 1 at.% indium‐doped film. The optical transmittance of all films is above 80% in visible range and blue shift in absorption edge was observed upon indium doping. The humidity level influences surface morphology, electrical, and optical properties of the doped films due to the strong moisture absorption nature of indium doping precursor. The performance of inverted OSC employing 1 at.% IZO as a buffer layer is higher than that of cell using un‐doped ZnO, which can be attributed to the higher optical transmittance and lower resistivity of doped film.

Controllable Formation of Zinc Oxide Micro‐ and Nanostructures via DUV Direct Patterning

“…Another important feature of ZnO is controllable electrical, optical, and magnetic performance by doping with small amount of elements. It was reported that doping ZnO with a little amount of group III elements, such as gallium, aluminum, and indium could significantly enhance conductivity. Also, many studies reported the observation of above‐room‐temperature ferromagnetism from transition‐metal‐doped ZnO .…”

Modifications of ZnO Interlayer to Improve the Power Conversion Efficiency of Organic Photovoltaic Cells

“…Zinc oxide is an n-type material having a wide band gap (3.3 eV) [39]. Zinc oxide becomes n type due to intrinsic defects of oxygen vacancy and the interstices occupied by excessive zinc [39].…”

“…Zinc oxide becomes n type due to intrinsic defects of oxygen vacancy and the interstices occupied by excessive zinc [39]. The heat treatment atmosphere and temperature influence the thin film conductivity [40,41].…”

Influence of In doping on electro-optical properties of ZnO films

“…Transparent conducting oxides (TCO's) in thin films have become very important for a variety of applications including gas sensors (Ferro et al 2008), optoelectronic devices (Shinde et al 2008), organic solar cells (Kyaw et al 2011) and others. Zinc oxide (ZnO) thin films present a particular importance due to their great optical transmittance in the visible wavelength range.…”