Researchers from Johannes Kepler University Linz, California Institute of Technology, University of Potsdam and HZB have shown that quasi‑2D perovskite solar cells (PSCs) can operate efficiently and stably over tens of days in low Earth orbit (LEO), underscoring their potential for lightweight, low‑cost space power systems. PSCs are particularly attractive for such applications because they combine solution‑processable, cost‑effective fabrication with ultrathin, flexible devices that deliver high power‑to‑weight ratios, making them well suited for deployable structures where reducing payload mass is critical.
The devices were tested on the Space Solar Power Demonstrator One (SSPD‑1) satellite, launched aboard SpaceX’s Transporter‑6 in early 2023. Over a 9‑month mission in LEO, SSPD‑1 investigated key technologies for cost‑effective space‑based solar power, including lightweight deployable structures, scalable wireless power transmission, and radiation‑tolerant photovoltaics. A dedicated payload, ALBA, evaluated several novel PV technologies, among them quasi‑2D PSCs. During the mission, ALBA recorded more than 3 million short‑circuit current density (Jsc) and open‑circuit voltage (Voc) measurements, alongside over 200 000 current density–voltage (J–V) sweeps, providing an extensive dataset on metal‑halide perovskite device behavior under real orbital conditions with repeated day–night cycles and thermal swings.
To connect these in‑orbit observations with controlled laboratory studies, the team fabricated structurally matched rigid and ultrathin (<3 µm) flexible quasi‑2D PSCs based on the absorber MBA2(Cs0.12MA0.88)6Pb7I22, where MBA (alpha‑methylbenzylammonium) is the bulky organic cation. MBA was selected to passivate defects and improve the energy‑level alignment at the perovskite/PEDOT:PSS interface, which enhances the open‑circuit voltage. In addition, dipoles formed between the sulfonic acid groups of PEDOT:PSS and the ammonium group of MBA facilitate charge extraction, decrease the effective acidity of PEDOT:PSS, and strengthen interlayer adhesion. Together, these interfacial effects lead to higher stability and performance, which is crucial for operation in harsh environments such as space.
Both rigid and flexible devices share the same absorber and transport layers, with PEDOT:PSS as the hole transport layer and a PCBM‑based electron transport layer, but they differ in front‑contact configuration and encapsulation. The rigid cells use ITO as the transparent front electrode and are encapsulated with epoxy and glass covers, providing strong environmental protection at the expense of added mass. The flexible cells employ PEDOT‑based transparent contacts and ultrathin polyurethane (PU) superstrates to preserve low weight and mechanical compliance. This dual‑platform design enables direct side‑by‑side assessment of orbital stability, radiation tolerance, and temperature‑dependent performance under both simulated and real space conditions.
In orbit, the champion rigid PSC exhibited relatively stable performance over a defined operating window rather than the full 9‑month mission duration. Over a 44‑day measurement interval that ended nearly 100 days after launch, the device experienced around 1600 orbital eclipse cycles and temperatures between approximately −25 and 35 °C, while maintaining about 80% of its initial power conversion efficiency. Laboratory measurements extended the temperature range from −80 to +80 °C and showed that both ultrathin and rigid PSCs behave practically identically between 0 and 40 °C, which corresponds well to the LEO conditions encountered by the satellite.
Radiation response was investigated using high‑energy proton irradiation on both rigid and flexible devices. For rigid PSCs on soda‑lime glass, the main radiation‑induced degradation manifested as a reduction in Jsc that was attributed primarily to radiative discoloration of the glass substrate, which lowers optical transmission, rather than intrinsic damage to the perovskite absorber. When the glass substrate was replaced with an ultrathin PET film, the PSCs displayed remarkable radiation resilience, retaining about 93% of their initial performance after a proton dose equivalent to 50 years in LEO. Flexible ultrathin devices likewise preserved over 92% of their efficiency under a comparable 50‑year‑equivalent proton dose, confirming that the perovskite stack and interfacial engineering are intrinsically radiation‑tolerant and that substrate and encapsulation choices dominate apparent degradation.
Despite this strong radiation hardness, the study identifies pre‑flight environmental exposure as a key bottleneck, particularly for ultrathin flexible devices with minimal encapsulation. Handling, moisture, oxygen, and other stressors during fabrication, integration, and launch preparations can induce degradation before the cells ever reach orbit, reducing the performance margin available during the mission. The authors therefore highlight several priorities for future development of space‑grade PSCs: improving polymer encapsulation strategies for flexible architectures, enhancing the resilience of charge transport layers, minimizing pre‑flight environmental exposure by integrating cells earlier into protected deployable structures, and systematically studying the effects of prolonged UV illumination on polymeric substrates and encapsulants.
By combining millions of in‑orbit measurements with systematic temperature and radiation tests on matched rigid and flexible devices, this work bridges the gap between short suborbital demonstrations and more extended orbital evaluation. The results show that quasi‑2D perovskite solar cells can maintain a large fraction of their initial efficiency over tens of days in LEO, tolerate radiation doses equivalent to several decades in orbit when paired with appropriate substrates, and offer high specific power thanks to their ultrathin form factor. These findings position PSCs as a promising, resilient, and low‑cost photovoltaic option for future space‑based solar power concepts, while also informing the design of durable, lightweight perovskite modules for terrestrial applications.
