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Page 2 of 22 Song et al. Energy Mater. 2026, 6, 600019

INTRODUCTION
Since the Apollo lunar landing in 1969 , human interest in space exploration and aerospace technology has
[1]
expanded dramatically. This milestone catalyzed sustained efforts to advance space science and engineering.
A key achievement is the establishment of the International Space Station (ISS), symbolizing international
collaboration and technological progress in long-term space habitation and experimentation . In recent
[2,3]
decades, governmental space agencies (e.g., National Aeronautics and Space Administration (NASA) , The
[4,5]
European Space Agency (ESA) , Japan Aerospace Exploration Agency (JAXA) , etc.) and private companies
[7]
[6]
(e.g., Space X , Blue Origin , etc.) have invested heavily to accelerate space exploration and to enhance
[9]
[8]
spacecraft technologies [Figure 1A] . This global effort has intensified, with remarkable developments for
[10]
long-duration missions, from orbital platforms to interplanetary travel. To support such missions, an
understanding of the space environment, including radiation, thermal cycling, vacuum, and micrometeoroid
exposure, is essential. Equally critical is the development of efficient energy systems for spacecraft and
satellites, which directly influence mission longevity and functionality. In our solar system, solar energy is the
most abundant and accessible power source, with photovoltaics as a key energy-harvesting technology.

Low Earth Orbit (LEO) missions require photovoltaic (PV) systems that are efficient, lightweight, and
durable in harsh space environments. Conventional space PV technologies, primarily crystalline silicon
(c-Si) and multi-junction III-V cells (e.g., Gallium arsenide (GaAs) [11,12] ), provide proven performances but
are limited by heavy and rigid panels, high manufacturing costs, and sensitivity to radiation. In contrast,
metal-halide perovskite solar cells (PSCs) have emerged as a groundbreaking thin-film PV technology,
exceeding 27% power conversion efficiency (PCE) in lab-scale devices [13,14] . Since PSCs can be fabricated as
ultralight flexible films with remarkable power-to-weight ratios, and their defect-tolerant crystal structure
enables remarkable radiation resistance. These features establish perovskites as a next-generation power
source in satellites and space systems [Figure 1B] , potentially enabling large deployable solar arrays while
[15]
reducing launch mass and cost.

This review provides a comprehensive overview of PSC technology specifically for LEO applications. As
shown in Figure 1C, detailed studies on space PSCs have been actively reported in recent literature.
Considering this, we examine key aspects such as the radiation tolerance, material stability, structural design
for lightweight and flexible modules, performance under space irradiation, and a comparison with
conventional space photovoltaics. Based on a technically grounded perspective, this work aims to support
near-term LEO demonstrations and future standardization efforts for PSC-based space power systems.

RADIATION TOLERANCE AND STABILITY OF PEROVSKITES IN SPACE CONDITIONS
Intrinsic radiation damage mechanisms and self-healing
Unlike terrestrial environments, solar cells in LEO are exposed to a broad spectrum of high-energy
radiations such as protons, electrons, heavy ions, Ultraviolet (UV) and X-rays, and γ-rays , which induce
[16]
severe degradation through lattice-defect formation and increased charge trapping, permanently damaging
conventional solar cells [Figure 2A] [17,18] . While Si and GaAs accumulate irreversible dislocations under such
irradiation [19-21] , metal-halide perovskites exhibit inherent defect tolerance and self-healing properties [22,23] .
Their soft ionic lattice can absorb and dissipate radiation energy via lattice vibrations and ion
rearrangements. Radiation-induced Frenkel-type defects such as vacancies or interstitials in perovskite are
readily annealed due to low formation energies (0.1-0.5 eV), which is much lower than those in Si
(2-5 eV) [24,25] . These mobile ionic defects can annihilate or self-heal on millisecond-to-second timescales,
assisted by strong electron-phonon coupling that facilitates lattice relaxation after particle impacts
[Figure 2B] . As a result, perovskites rapidly return to their original crystalline state, although they are
[26]
temporarily disordered by radiation. This unique radiation resilience has been observed in numerous studies
on PSCs, and is absent in conventional covalent semiconductors .
[27]