Perovskites
Perovskite Thin Films for Solar Cells
Perovskite thin films have become a key focus for many material research labs after its initial proposal as an option for a new high efficiency solar cell in the early 2000s. With this ground-breaking new option (replacing the previous iterations of organic photovoltaics) allowing for efficiencies to increase by 20% compared to previous versions.
Not only were these new organic layers better at absorbing light, the active layer proved to be easier to extract electricity from also. The main upside however in the advancement of perovskite research as an active layer is in their relative cost compared to other options such as crystalline silicon PV. If advancements can continue to be made, they could offer a potential avenue for production-scale solar cells and in doing so, help the widespread distribution of renewable energy.
In terms of the active layer itself – a thin film of metal-halide perovskite must be deposited onto the cell and then pinned between layers to direct electron flow through the active layer and into the metal contacts below.
Deposition of perovskites can happen in various ways from spin coating to vapour deposition. At Korvus Technology we have developed our systems to facilitate processes and are constantly improving our systems to work with the newest developments in active research.
Due to the volatile nature of metal-halide perovskites and the need to form them as a compound on the surface of the cell, rather than evaporating them from the source directly, co-evaporation of separate pre-cursor materials at once.
The HEX series of high-modular PVD systems works perfectly under these conditions, with its ORCA low-temperature evaporation source, the evaporation conditions can be closely controlled to allow for a uniform and stable deposition, a rotating, heated table is used to help the perovskite layer set and then new layer can be deposited on top in the same run. This is all controlled via the Korvus controlled software and can be preprogrammed to run entire deposition trials without any user input.
In order to further improve the safety and longevity of the system, the chamber should be built into a glovebox to avoid any damages through reactions to the chamber’s internal components and the side panels. A stainless-steel chamber option is also recommended to avoid any reactions from the precursors with aluminium.
FISSION- Magnetron Sputtering Source
ORCA - Low Temperature Evaporation
TAU - Electron Beam Evaporation
Frequently Asked Questions
What is a Perovskite?
A perovskite from PVD refers to perovskite materials that are deposited onto substrates using Physical Vapor Deposition techniques, such as evaporation or sputtering. This method is popular in the production of perovskite solar cells because it offers high control over the material properties, film quality, and scalability for large-area production. Despite the promise, challenges like moisture sensitivity, film uniformity, and toxicity (for lead-based perovskites) remain areas of ongoing research.
How is PVD used to research Perovskites?
Physical Vapor Deposition (PVD) is a crucial tool in researching perovskites, particularly in the development of perovskite solar cells and other optoelectronic devices. PVD allows researchers to precisely control the deposition of perovskite materials, which is important for understanding their properties, optimizing their performance, and investigating new perovskite compositions and structures.
What coatings are typically studied in Perovskite research using PVD?
In perovskite research using PVD, several coatings are deposited to enhance the performance, stability, and efficiency of perovskite-based devices, particularly solar cells. These coatings include electron transport layers (ETLs), hole transport layers (HTLs), electrode layers, the active perovskite layer itself, and buffer/passivation layers. Each of these coatings plays a vital role in charge transport, device stability, and efficiency, and PVD techniques like sputtering and evaporation allow researchers to precisely control the deposition of these materials for optimal device performance.
What Are The key concerns when researching Perovskits using PVD?
Moisture sensitivity and the need for proper encapsulation.
Achieving correct stoichiometry and avoiding defects in perovskite films.
Controlling crystallization and film morphology for better charge transport.
Interface quality between the perovskite and other layers (e.g., ETL, HTL).
Scalability challenges when moving from lab-scale to large-area deposition.
Managing precursor materials and ensuring proper reaction for uniform perovskite formation.
Achieving uniform film thickness and consistent quality.
Environmental concerns related to lead-based perovskites.
Thermal degradation and the need for long-term stability.
By carefully addressing these challenges, researchers can optimize PVD processes for high-performance and long-lasting perovskite-based devices.
What are the PVD system considerations for Peroskite research?
For perovskite research, the system will need to be connected to a glovebox –