2D/3D Perovskite Heterojunction for Stability and Efficiency
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Solution Overview
Problem
Perovskite solar cells (PSCs) have achieved high power conversion efficiencies but suffer from low stability, which is unacceptable for real-world applications, and the formation of detrimental crystallographic δ-phase during surface treatment leads to efficiency losses.
Innovation Solution
A selective precursor dissolution (SPD) strategy is employed to grow a thin 2D perovskite layer on top of a bulk 3D perovskite cell, using a solvent that selectively dissolves the 2D precursor while retaining the high-quality 3D underlayer, preventing δ-phase formation and passivating surface and grain boundary defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional surface treatment methods are used to improve perovskite solar cell stability, then device stability is improved, but detrimental δ-phase formation occurs leading to efficiency loss
Solution Approach 1:
The invention changes the chemical composition parameters of the perovskite layer by incorporating a 2D perovskite component into the conventional 3D perovskite structure. This compositional parameter change allows the formation of a 3D/2D heterojunction that provides stability without forming the detrimental δ-phase, thus resolving the contradiction between stability improvement and efficiency loss
Solution Approach 2:
The invention creates a composite material structure by combining 3D perovskite and 2D perovskite phases to form a 3D/2D heterojunction. This composite approach leverages the stability advantages of 2D perovskite while maintaining the high efficiency characteristics of 3D perovskite, thereby achieving both improved stability and preserved efficiency
2Productivity
If high power conversion efficiency is achieved in perovskite solar cells, then energy conversion performance is improved, but operational stability deteriorates to unacceptable levels
Solution Approach 1:
The invention applies local quality modification by creating a 2D perovskite layer specifically at the surface and grain boundaries of the 3D perovskite structure. This localized modification provides enhanced stability at critical interfaces while preserving the bulk 3D perovskite's high efficiency characteristics, thus resolving the contradiction between efficiency and stability
3Reliability
If a 2D perovskite layer is grown on 3D perovskite to passivate defects, then device stability is improved, but the complexity of the fabrication process increases
Solution Approach 1:
The invention merges the 2D perovskite layer formation process with the existing 3D perovskite fabrication process into a single integrated step. By combining these processes, the 2D/3D heterojunction is formed during the same fabrication sequence, reducing overall process complexity while maintaining the stability benefits of the 2D passivation layer
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a record-certified stabilized power conversion efficiency of 22.6% with enhanced operational stability and low open-circuit-voltage loss, maintaining high efficiency over 200 hours under full AM 1.5 G illumination without Cesium and Rubidium additives.
Implementation Method 1
using a solvent that selectively dissolves the 2D precursor while retaining the high-quality 3D underlayer
Implementation Method 2
Perovskite solar cells (PSCs) have achieved high power conversion efficiencies
Data Source
AI summary
A photovoltaic device and method of manufacturing the device are described.