Skip to main content
Home
Department Of Physics text logo
  • Research
    • Our research
    • Our research groups
    • Our research in action
    • Research funding support
    • Summer internships for undergraduates
  • Study
    • Undergraduates
    • Postgraduates
  • Engage
    • For alumni
    • For business
    • For schools
    • For the public
Menu
CMP
Credit: Jack Hobhouse

Prof Henry Snaith FRS

Professor of Physics

Sub department

  • Condensed Matter Physics

Research groups

  • Snaith group
  • Advanced Device Concepts for Next-Generation Photovoltaics
Henry.Snaith@physics.ox.ac.uk
Robert Hooke Building, room G21
  • About
  • Publications

Interfacial Energetics Reversal Strategy for Efficient Perovskite Solar Cells.

Advanced materials (Deerfield Beach, Fla.) (2025) e2503110

Authors:

Sheng Jiang, Shaobing Xiong, Zhongcheng Yuan, Yafang Li, Xiaomeng You, Hongbo Wu, Menghui Jia, Zhennan Lin, Zaifei Ma, Yuning Wu, Yefeng Yao, Xianjie Liu, Junhao Chu, Zhenrong Sun, Mats Fahlman, Henry J Snaith, Qinye Bao

Abstract:

Reducing heterointerface nonradiative recombination is a key challenge for realizing highly efficient perovskite solar cells (PSCs). Motivated by this, a facile strategy is developed via interfacial energetics reversal to functionalize perovskite heterointerface. A surfactant molecule, trichloro[3-(pentafluorophenyl)propyl]silane (TPFS) reverses perovskite surface energetics from intrinsic n-type to p-type, evidently demonstrated by ultraviolet and inverse photoelectron spectroscopies. The reconstructed perovskite surface energetics match well with the upper deposited hole transport layer, realizing an exquisite energy level alignment for accelerating hole extraction across the heterointerface. Meanwhile, TPFS further diminishes surface defect density. As a result, this cooperative strategy leads to greatly minimized nonradiative recombination. PSCs achieve an impressive power conversion efficiency of 25.9% with excellent reproducibility, and a nonradiative recombination-induced qVoc loss of only 57 meV, which is the smallest reported to date in n-i-p structured PSCs.
More details from the publisher
More details
More details

Inter‐Layer Diffusion of Excitations in 2D Perovskites Revealed by Photoluminescence Reabsorption

Advanced Functional Materials Wiley (2025)

Authors:

Jiaxing Du, Marcello Righetto, Manuel Kober‐Czerny, Siyu Yan, Karim A Elmestekawy, Henry J Snaith, Michael B Johnston, Laura M Herz

Abstract:

<jats:title>Abstract</jats:title><jats:p>2D lead halide perovskites (2DPs) offer chemical compatibility with 3D perovskites and enhanced stability, which are attractive for applications in photovoltaic and light‐emitting devices. However, such lowered structural dimensionality causes increased excitonic effects and highly anisotropic charge‐carrier transport. Determining the diffusivity of excitations, in particular for out‐of‐plane or inter‐layer transport, is therefore crucial, yet challenging to achieve. Here, an effective method is demonstrated for monitoring inter‐layer diffusion of photoexcitations in (PEA)<jats:sub>2</jats:sub>PbI<jats:sub>4</jats:sub> thin films by tracking time‐dependent changes in photoluminescence spectra induced by photon reabsorption effects. Selective photoexcitation from either substrate‐ or air‐side of the films reveals differences in diffusion dynamics encountered through the film profile. Time‐dependent diffusion coefficients are extracted from spectral dynamics through a 1D diffusion model coupled with an interference correction for refractive index variations arising from the strong excitonic resonance of 2DPs. Such analysis, together with structural probes, shows that minute misalignment of 2DPs planes occurs at distances far from the substrate, where efficient in‐plane transport consequently overshadows the less efficient out‐of‐plane transport in the direction perpendicular to the substrate. Through detailed analysis, a low out‐of‐plane excitation diffusion coefficient of (0.26 ± 0.03) ×10<jats:sup>−4</jats:sup> cm<jats:sup>2</jats:sup> s<jats:sup>−1</jats:sup> is determined, consistent with a diffusion anisotropy of ≈4 orders of magnitude.</jats:p>
More details from the publisher
More details

Probing ionic conductivity and electric field screening in perovskite solar cells: a novel exploration through ion drift currents.

Energy & environmental science 18:3 (2025) 1385-1397

Authors:

Matthias Diethelm, Tino Lukas, Joel Smith, Akash Dasgupta, Pietro Caprioglio, Moritz Futscher, Roland Hany, Henry J Snaith

Abstract:

It is widely accepted that mobile ions are responsible for the slow electronic responses observed in metal halide perovskite-based optoelectronic devices, and strongly influence long-term operational stability. Electrical characterisation methods mostly observe complex indirect effects of ions on bulk/interface recombination, struggle to quantify the ion density and mobility, and are typically not able to fully quantify the influence of the ions upon the bulk and interfacial electric fields. We analyse the bias-assisted charge extraction (BACE) method for the case of a screened bulk electric field, and introduce a new characterisation method based on BACE, termed ion drift BACE. We reveal that the initial current density and current decay dynamics depend on the ion conductivity, which is the product of ion density and mobility. This means that for an unknown high ion density, typical in perovskite solar absorber layers, the mobility cannot be directly obtained from BACE measurements. We derive an analytical model to illustrate the relation between current density, conductivity and bulk field screening, supported by drift-diffusion simulations. By measuring the ion density independently with impedance spectroscopy, we show how the ion mobility can be derived from the BACE ion conductivity. We highlight important differences between the low- and high-ion density cases, which reveal whether the bulk electric field is fully screened or not. Our work clarifies the complex ion-related processes occurring within perovskite solar cells and gives new insight into the operational principles of halide perovskite devices as mixed ionic-electronic conductors.
More details from the publisher
More details
More details

Determining Parameters of Metal-Halide Perovskites Using Photoluminescence with Bayesian Inference

PRX Energy American Physical Society (APS) 4:1 (2025) 13001

Authors:

Manuel Kober-Czerny, Akash Dasgupta, Seongrok Seo, Florine M Rombach, David P McMeekin, Heon Jin, Henry J Snaith

Abstract:

<jats:p>In this work, we demonstrate that time-resolved photoluminescence data of metal halide perovskites can be effectively evaluated by combining Bayesian inference with a Markov-chain Monte-Carlo algorithm and a physical model. This approach enables us to infer a high number of parameters that govern the performance of metal halide perovskite-based devices, alongside the probability distributions of those parameters, as well as correlations among all parameters. Via studying a set of halfstacks, comprising electron- and hole-transport materials contacting perovskite thin films, we determine surface recombination velocities at these interfaces with high precision. From the probability distributions of all inferred parameters, we can simulate intensity-dependent photoluminescence quantum efficiency and compare it to experimental data. Finally, we estimate mobility values for vertical charge-carrier transport, which is perpendicular to the plane of the substrate, for all samples using our approach. Since this mobility estimation is derived from charge-carrier diffusion over the length scale of the film thickness and in the vertical direction, it is highly relevant for transport in photovoltaic and light-emitting devices. Our approach of coupling spectroscopic measurements with advanced computational analysis will help speed up scientific research in the field of optoelectronic materials and devices and exemplifies how carefully constructed computational algorithms can derive valuable plurality of information from simple datasets. We expect that our approach can be expanded to a variety of other analysis techniques and that our method will be applicable to other semiconductors.</jats:p> <jats:sec> <jats:title/> <jats:supplementary-material> <jats:permissions> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material> </jats:sec>
More details from the publisher

Determining material parameters of metal halide perovskites using time-resolved photoluminescence

PRX Energy American Physical Society 4:1 (2025) 013001

Authors:

Manuel Kober-Czerny, Akash Dasgupta, Seongrok Seo, Florine Rombach, David McMeekin, Heon Jin, Henry Snaith

Abstract:

In this work we demonstrate that time-resolved photoluminescence data of metal halide perovskites can be effectively evaluated by combining Bayesian inference with a Markov-Chain Monte-Carlo algorithm and a physical model. This approach enables us to infer a high number of parameters which govern the performance of metal halide perovskite-based devices, alongside the probability distributions of those parameters, as well as correlations among all parameters. Via studying a set of "half-stacks’‘, comprising electron and hole transport materials contacting perovskite thin-films, we determine surface recombination velocities at these interfaces with high precision. From the probability distributions of all inferred parameters, we can simulate intensity-dependent photoluminescence quantum efficiency and compare it to the experimental data. Finally, we estimate mobility values for the "vertical’’ charge carrier transport, that perpendicular to the plane of the substrate, for all samples using our approach. Since this mobility estimation is derived from charge carrier diffusion over the length-scale of the film thickness and in the vertical direction, it is highly relevant to transport in photovoltaic and light emitting devices. Our approach of coupling spectroscopic measurements with advanced, computational analysis will help speed up scientific research in the field of optoelectronic materials and devices and exemplifies how carefully constructed computational algorithms can derive valuable plurality of information from simple datasets. We expect that our approach will be expandable to a variety of other analysis techniques and that our method will be applicable to other semiconductors.
More details from the publisher
Details from ORA

Pagination

  • Current page 1
  • Page 2
  • Page 3
  • Page 4
  • Page 5
  • Page 6
  • Page 7
  • Page 8
  • Page 9
  • …
  • Next page Next
  • Last page Last

Footer Menu

  • Contact us
  • Giving to the Dept of Physics
  • Work with us
  • Media

User account menu

  • Log in

Follow us

FIND US

Clarendon Laboratory,

Parks Road,

Oxford,

OX1 3PU

CONTACT US

Tel: +44(0)1865272200

University of Oxfrod logo Department Of Physics text logo
IOP Juno Champion logo Athena Swan Silver Award logo

© University of Oxford - Department of Physics

Cookies | Privacy policy | Accessibility statement

Built by: Versantus

  • Home
  • Research
  • Study
  • Engage
  • Our people
  • News & Comment
  • Events
  • Our facilities & services
  • About us
  • Current students
  • Staff intranet