Related Experiment Video
Updated: Aug 5, 2026
11:38
Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance
Published on: February 27, 2017
PFN-Br Modified Buried Interface Enhanced Charge Extraction in Inverted Wide-Bandgap Perovskite Solar Cells
Yuying Wang1,2,3,4,5, Felix T Eickemeyer6, Pengyang Wang1,2,3,4,5
1Institute of Photoelectronic Thin Film Devices and Technology, Renewable Energy Conversion and Storage Center, Nankai University, Tianjin, P. R. China.
Small (Weinheim an Der Bergstrasse, Germany)
|July 30, 2026
Summary
Wide-bandgap perovskite solar cells (WBG PSCs) face voltage losses due to energy-level mismatch and defects. A new PFN-Br interlayer improves hole extraction, boosting WBG PSC efficiency and voltage.
Area of Science:
- Materials Science
- Renewable Energy
- Photovoltaics
Background:
- Tandem solar cells (TSCs) show promise, but wide-bandgap perovskite solar cells (WBG PSCs) used as top cells exhibit significant open-circuit voltage (VOC) losses.
- Deeper valence bands in WBG PSCs cause energy-level misalignment with conventional hole transport materials, and crystallization defects further degrade performance.
Purpose of the Study:
- To address VOC losses and interface defects in WBG PSCs.
- To introduce a novel passivation strategy using a PFN-Br interlayer to enhance hole extraction and device performance.
Main Methods:
- Incorporation of poly[9,9-bis(3'-(N,N-dimethyl)-N-ethylammoniumpropyl)-2,7-fluorene-alt-2,7-(9,9-dioctylfluorene)] dibromide (PFN-Br) as an interlayer between 2PACz and the perovskite absorber.
- Characterization of the PFN-Br interlayer's effect on energy-level alignment and non-radiative recombination suppression.
Main Results:
- PFN-Br effectively suppresses non-radiative recombination through its bromide-counterion ammonium groups.
- The interlayer tunes energy-level alignment, facilitating more efficient hole extraction in WBG PSCs.
- PFN-Br-modified WBG PSCs achieved a champion power conversion efficiency of 23.15% and a high VOC of 1.281 V for a 1.67 eV bandgap.
Conclusions:
- PFN-Br serves as an effective passivation strategy for WBG PSCs.
- The developed interlayer enhances hole extraction and significantly boosts device efficiency and VOC.
- This approach offers a promising route for improving the performance of perovskite-based tandem solar cells.
Related Concept Videos
01:11P-N junction
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
01:16Biasing of P-N Junction
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...