Organometallic Dyes Modification on the NiOx Hole Transport Layer for Organic Photovoltaic Application

Abstract

Nickel oxide (NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> ) has proved as an efficient hole transport layer (HTL) for perovskite solar cells (PSCs) with inverted structure. However, NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> is rarely adopted as HTL for standard structure organic photovoltaics (OPVs) with PEDOT:PSS still widely used despite their drawbacks that could affect the device's operational stability. Passivation of NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> /perovskite interface with self-assembled monolayer or organometallic dye could increase the performance of single junction inverted PSCs by suppressing defect densities at the interface of NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> . However, their application in OPVs has not been explored. This work investigates the effect of NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> passivation with various organometallic dye molecules (N719, C106, N3, N749, Z907) for OPV application. Our results show that only NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> -based devices modified with N3 exhibit an efficiency increase compared to those with pristine NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> HTL. This work provides insights into the role of the energy alignment between the NiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> interface with the OPV's active layer.