Nickel doped zinc oxide electron transport layer for improved performance of P3HT: PC71BM based Inverted Organic Solar Cell

Abstract

Zinc oxide (ZnO) is one of the widely used electron transport layers (ETLs) for organic solar cells (OSCs). In this study, Nickel doped zinc oxide (ZnO:Ni) thin films were prepared by using a simple sol gel technique by varying the Nickel concentration (2%,3% and 5% by mole) and used in inverted organic solar cells. The thin films exhibited better optical, structural and morphological properties upon nickel doping. Furthermore, a device with a 3 mol.% Ni dopant had the highest power conversion efficiency (PCE) of about 3.72 %, which is 50% higher than the PCE of the ZnO-only device (2.48%). The improved electrical conductivity, short circuit current, fill factor, charge generation and exciton dissociation are the primary reasons for the PCE enhancement. Furthermore, the ETL's increased electrical conductivity by more than one fold increases the photocurrent from 9.6 to 13.6 mA/cm2 . In addition, due to improved morphology of Ni:ZnO thin films, the fill factor increased by more than 14%. As a result, Ni doping could be a promising, low-cost approach to improve the performance of inverted OSC.

Zinc Oxide (Zno) Is One Of The Widely Used Electron Transport Layers (Etls) For Organic Solar Cells (Oscs). In This Study, Nickel Doped Zinc Oxide (Zno:ni) Thin Films Were Prepared By Using A Simple Sol Gel Technique By Varying The Nickel Concentration (2%,3% And 5% By Mole) And Used In Inverted Organic Solar Cells. The Thin Films Exhibited Better Optical, Structural And Morphological Properties Upon Nickel Doping. Furthermore, A Device With A 3 Mol.% Ni Dopant Had The Highest Power Conversion Efficiency (Pce) Of About 3.72 %, Which Is 50% Higher Than The Pce Of The Zno-Only Device (2.48%). The Improved Electrical Conductivity, Short Circuit Current, Fill Factor, Charge Generation And Exciton Dissociation Are The Primary Reasons For The Pce Enhancement. Furthermore, The Etl's Increased Electrical Conductivity By More Than One Fold Increases The Photocurrent From 9.6 To 13.6 Ma/Cm2. In Addition, Due To Improved Morphology Of Ni:zno Thin Films, The Fill Factor Increased By More Than 14%. As A Result, Ni Doping Could Be A Promising, Low-Cost Approach To Improve The Performance Of Inverted Osc