Enhancement of Perovskite Back-Contacted Micro-Modules via Surface Engineering Strategies and Process Development

Abstract

This thesis addressed the challenge of transitioning laboratory scale charge transport layer (CTL) materials of a novel back-contacted micro-module (BCMM) solar architecture, which consisted of individual microgroove cells, to industrial roll to roll (R2R) production by developing scalable thin film processing techniques. Through surface modifications and solution based formulation tuning, the work established a robust framework for enhancing BCMM functionality whilst maintaining manufacturability. Key innovations include: • A plasma treatment protocol applied to the BCMM that modified hole transport layer (HTL)surface properties and functionality with minimal detriment to the electron transport layer (ETL), enabling power conversion efficiencies (PCEs) of up to 1.7 ± 0.5 % from previously nonfunctional devices. • Fundamental processing and deposition of reactive electron (e)-beam evaporated nickel oxide (NiOx) HTLs and tin oxide (SnOx) ETLs were optimised for material property consistency and performance after a R2R method of deposition, implementing a constant oxygen flow rate into the reaction chamber for NiOx HTLs and steady pressure conditions for SnOx ETLs. The PCE of the BCMM increased from 1.7% to a champion of 5.5 ± 1.1 %. • A [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl] phosphonic acid (Me−4Pacz) in an isopropanol (IPA) based self assembled monolayer (SAM), deployed via a solution processed deposition strategy, enhanced device performance metrics. The champion PCE increased from 5.5% to 8 ± 0.9 %. Novelty lies in the proposed preferential binding mechanism of Me − 4Pacz phosphonic binding sites to NiOx surface hydroxyls, potentially facilitated by a buckminsterfullerene (C60) blocking layer deposited on the SnOx ETL on the opposing groove wall.