Glove Boxes for Perovskite Solar Cell Applications

In the fabrication process of perovskite solar cells, the light-sensitive active layer and functional interfaces are highly sensitive to moisture and oxygen in the ambient atmosphere. Minor environmental fluctuations may lead to material degradation, device efficiency decay, and other issues. Therefore, performing fabrication operations inside glove boxes has become the standard operating procedure in the industry. The overall performance of a glove box directly determines the controllability and reproducibility of the perovskite solar cell fabrication process, as well as the performance and stability of the finished devices. To ensure successful fabrication, several key precautions for glove boxes must be strictly controlled.

1. Maintain Water and Oxygen Content < 1 ppm Inside the Glove Box

Perovskite fabrication materials exhibit poor chemical stability. Contact with moisture and oxygen will cause their decomposition and oxidation, thereby deteriorating the photoelectric conversion efficiency and long-term stability of the solar cells.

Water and oxygen content are critical indicators for glove box environmental control. For perovskite solar cell fabrication, the water and oxygen content inside the chamber must be stably controlled at an extremely low level of < 1 ppm. This is the fundamental prerequisite for preserving the intrinsic properties of perovskite materials, achieving high-quality crystal growth, and forming stable interfaces.

To ensure that the water and oxygen levels inside the glove box can be stably maintained below 1 ppm, it is necessary to guarantee the airtightness of the glove box body (including viewing windows, gloves, sealing rings, etc.) to completely block the penetration of external impurities; use high-purity inert gas to prevent impure working gas from introducing excessive impurities into the chamber; meanwhile, strictly monitor and regularly regenerate or replace the purification materials to maintain their continuous and efficient deep purification capacity. Through these measures, the low-water-and-oxygen atmosphere inside the glove box can be sustained stably.

2. Clean Environment Inside the Perovskite Glove Box

A clean internal environment is an important prerequisite to avoid impurity contamination of perovskite materials. Especially in key fabrication steps such as thin film deposition, tiny dust particles may induce defects in the devices. The glove box can be equipped with an FFU ultra-clean filtration system on the top of the chamber. Driven by a dust removal fan, the gas inside the glove box is filtered through H14 high-efficiency or U15 ultra-high-efficiency filter cartridges to form a stable unidirectional vertical laminar flow, which effectively removes particles in the working area. The cleanliness of the operating zone inside the glove box can reach Class 10 or Class 100 standards, providing a clean environment for high-precision fabrication of perovskite solar cells.

After flowing through the bottom area, the gas inside the chamber returns to the dust removal system through a circulation pipeline, forming a closed-loop circulation filtration mode. The stable clean environment inside the glove box can be consistently maintained.

3. Treatment of Organic Solvents and Temperature Control

1) Treatment of Organic Solvents

During the fabrication of perovskite solar cells, organic solvents (such as dimethylformamide DMF and dimethyl sulfoxide DMSO, etc.) evaporate from the solution and accumulate inside the glove box during solution preparation and device post-treatment. These volatile organic solvents may interact with perovskite materials, affect device performance, and also pose potential risks to the glove box sensors.

To solve this problem, the "purge" function of the glove box can be activated to discharge the gas mixed with organic solvents inside the chamber through inert working gas replacement. At the same time, it is recommended to install an enlarged organic solvent adsorber to deeply adsorb residual organic solvents inside the chamber using adsorption materials, further reducing their concentration.

2) Temperature Control

The preparation of perovskite solutions requires the addition of calcium and titanium compounds into organic solvents, together with certain surfactants and stabilizers to improve solution stability. These materials must be stored inside a glove box with an anhydrous, oxygen-free, and dust-free environment.

Some fabrication solutions are sensitive to temperature. Temperature fluctuations may lead to uneven solution concentration, abnormal crystallization rate, and other problems. To address this, an industrial air conditioning system can be installed inside the glove box to precisely control the internal temperature within the suitable range of 15–20 °C, providing a stable temperature environment for solution preparation, thin film growth, and other steps, and ensuring the consistency of experimental conditions.