Nb-Doping TiO₂ Electron Transporting Layer for Efficient Perovskite Solar Cells

Abstract

For improvement of the electron transporting and charge separation in the interface of TiO2 and perovskite, the smooth and compact Nb-doping TiO2 electron transporting layer was successfully prepared by a hydrolysis–pyrolysis method using an acidic titanium isopropoxide solution in isopropanol and niobium chloride (NbCl5) as the niobium source. The planar perovskite solar cells with the undoped TiO2 electron transporting layer gave a photoelectric conversion efficiency (PCE) of 14.56%, while the planar perovskite solar cells with the 2.5% Nb-doping TiO2 electron transporting layer obtained a PCE of 15.97%. When the TiO2 nanorod array was introduced between the 2.5% Nb-doping TiO2 electron transporting layer and the perovskite thin film, the corresponding perovskite solar cells achieved a PCE of 18.88% under illumination of simulated AM 1.5 sunlight (100 mA cm–2).

Influence of Lithium and Lanthanum Treatment on TiO2 Nanofibers and Their Application in n‐i‐p Solar Cells

“…Despite these benefits, NFs suffer from low surface areas which is disadvantageous in the field of solar cells, particularly for dye‐sensitized solar cells (DSSCs) where it leads to low dye uptake. While the addition of NPs has been reported to circumvent such limitations in NF‐based photoelectrodes, doping TiO 2 with cations and anions has been previously used in particulate‐based systems to modify the electronic properties of TiO 2 . Since the types of dopant will have a different influence on a material's characteristics, they should be selected based on the alterations that are required to be achieved.…”

A universal solution processed interfacial bilayer enabling ohmic contact in organic and hybrid optoelectronic devices

“…26 TiO 2 doped with Nb has been demonstrated to be an efficient ETL in perovskite and dye-sensitised photovoltaics, as well as in photocatalytic applications and battery electrodes, given its improvement in carrier density over pristine TiO 2 . [31][32][33][34][35][36][37][38][39][40][41] Light and dark field transmission electron microscopy (TEM) images of TiO 2 nanoparticles ( Fig. 1a and b, respectively) exhibit a lattice spacing of 0.29 nm between both {2 1 1} and {À2 1 À1} planes, with an average nanoparticle size of 7 nm.…”

Metal Oxide Charge Transport Layers for Efficient and Stable Perovskite Solar Cells

“…Nb doping in TiO 2 led to a positive shift in flat band potential ( V fb ) and an improvement in conductivity compared with undoped TiO 2 , which enhanced the electron injection and extraction in PSCs, improving the device performance and reducing hysteresis. More recently, Xiao et al developed Nb‐doped TiO 2 nanorod array using a hydrolysis‐pyrolysis method as an ETL for PSCs . Enhanced electrical properties of TiO 2 nanorod array improved the device performance up to about 19%.…”