Vapor deposited metal halide perovskites
Our group develops vapor and hybrid vapor-solution routes to fabricate metal halide perovskites. We use it both to make good solar cells and to reach compositions that other methods cannot deliver at all.
Why vapor deposition?
Composition control in vapor deposition of perovskites is challenging. The materials combine many elements, mix organic and inorganic components in one lattice, and those components differ enormously in solubility and volatility. Every deposition method trades one kind of control for another.
Solution processing is widely studied and highly optimized, and it holds most efficiency records. Vapor processing is solvent-free and industrially relevant, but far less explored ‚ the accumulated know-how simply isn't there yet. Between them sits the hybrid sequential approach: deposit the inorganic framework from the vapor phase, then introduce the organic component from solution.
Three families of methods for perovskite absorber deposition. The hybrid sequential process combines a vapor-deposited inorganic scaffold with a solution-processed organic conversion step.
The method landscape
The established vapor methods are **co-evaporation**, in which precursors arrive at the substrate simultaneously from separate sources, and **sequential evaporation**, in which they are stacked and then interdiffused. Both are mature enough to make devices, and both constrain what compositions you can reach.
A second group of methods is emerging: closed space sublimation, vapor transport and CVD, sputtering, and pulsed laser deposition. These are less developed but open up parameter space that evaporation may not access ‚ particularly for complex, multi-cation, and low-dimensional complex compositions.
We surveyed this whole field in *Chemical Reviews* (2026). If you are new to vapor-deposited perovskites, start there.
> K. Zanoni, S. Kralj, X. Chin, A. Bruno, H. Bolink, M. Morales-Masis. Chem. Rev. (2026). https://doi.org/10.1021/acs.chemrev.5c00897
> T. Soto-Montero, M. Morales-Masis. ACS Energy Lett. 9, 4199‚ 4208 (2024). https://doi.org/10.1021/acsenergylett.4c01466
> T. Soto-Montero, W. Soltanpoor, M. Morales-Masis. APL Mater. 8, 110903 (2020). https://doi.org/10.1063/5.0027573
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Pulsed laser deposition: a dry, single-source route
Pulsed laser deposition (PLD) transfers material from a solid target to a substrate using a focused laser pulse. For oxides this is standard practice. For metal halide perovskites‚ which contain fragile organic cations ‚ the obvious objection is that the molecules should not survive the process.
They do, and demonstrating that has been a substantial part of our work.
How it works? We synthesize the target mechanochemically, then ablate it at low fluence (0.2 to 0.4 J/cm2) onto a substrate held at room temperature. Because the target is a single source, its composition is the primary control handle.
Illustration of the MHP PLD process developed by the group. Animation made by Tatiana Soto Montero (https://scienceinmotion.myportfolio.com/work)
*Two-step PLD of metal halide perovskites: mechanochemical target synthesis, followed by laser ablation and film growth at room temperature.*
The molecules survive!
Using magic-angle-spinning solid-state NMR ‚ measured on films directly, without scratching material off multiple substrates‚ together with XPS, we confirmed the integrity of both MA+ and FA+ in laser-deposited MAFAPbI3, and quantified their ratio in the film against the target.
https://doi.org/10.1021/acs.chemmater.4c00935
And the films make good devices.
PLD-grown MAFAPbI3 absorbers of roughly 420 nm, deposited on ITO/2PACz, work in p-i-n solar cells. This was, to our knowledge, the first demonstration that a single-source laser-deposited perovskite could function as a device-quality absorber.
T. Soto-Montero et al. Joule (2024). https://doi.org/10.1016/j.joule.2024.09.001
S. Kralj, M. Morales-Masis et al. Adv. Energy Mater. 2025, 15 https://doi.org/10.1002/aenm.202406033
Hybrid sequential deposition
With the goal of accelerating the deposition speed of the metal halide perovskites, we look into the hybrid route. In hybrid sequential deposition we vapor-deposit the inorganic scaffold (with a fast PLD!) and convert it to perovskite with an organohalide solution.
Fast deposition without penalty.
Deposition rate is one of the parameters that usually decides whether a vacuum process is industrially interesting. By tuning laser repetition rate across 4, 16 and 32 Hz we reached scaffold deposition rates from 13 to over 100 nm/min. SEM shows the same grainy, porous, nanoplate-structured scaffold at every rate, and EDX shows near-stoichiometric transfer at every rate. In other words, going roughly eight times faster costs nothing in morphology or composition. Ref. S. Kralj, K. Artuk, M. Nales, C. Wolff, M. Morales-Masis. *ACS Energy Lett.* **11** (2026). https://doi.org/10.1021/acsenergylett.5c04010
Beyond lead iodide: compositional versatility
The reason we invest in laser deposition is not only that it makes good MAFA perovskite. It is that a single-source, room-temperature, solvent-free method lets us attempt compositions that have no established synthesis route‚ including materials that existed so far mainly as computational predictions.
- 10.1016/j.matt.2023.10.003 External Link
- https://doi.org/10.1038/s41699-025-00571-3
- https://doi.org/10.1038/s44160-024-00717-z
- https://doi.org/10.1021/acs.chemmater.3c01349
- https://doi.org/10.1021/acs.chemmater.1c02054
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Automation and high-throughput optimization
(in progress)
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**Related:** the absorber is only one layer in the stack. See [Transparent Conducting Electrodes](/research/transparent-conducting-electrodes) for our work on the contacts around it.