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Song et al. Energy Mater. 2026, 6, 600019 Page 11 of 22

glass [143,144] . They also demonstrated that some irradiated PSCs enhanced J and efficiency post-irradiation,
sc
attributed to a self-healing mechanism. Proton irradiation may dissociate C-H and N-H bonds, releasing H +
ions, which subsequently passivate defect sites once irradiation, restoring or even improving device
performance. According to a report by Lang et al., exposure to a 20 MeV proton beam contributes to
passivation of deep traps at the perovskite/TiO interface, resulting in improved charge collection with
2
slightly increased FF and V oc [145] .

In the case of γ-rays, which are highly penetrating and difficult to shield [146] , Cs MA FA Pb(Br I )
0.10
0.17 0.83
0.15
0.75
exhibits PL enhancement and red-shift under up to 5,000 gray (Gy), with Hoke effect indicating halide
segregation and bandgap formation under illumination. Boldyreva et al. [147] also reported a reversible
mechanism in perovskites: upon irradiation, MAPbI decomposes into methylammonium iodide (MAI) and
3
PbI , with MAI further breaking down into NH and CH I. γ-rays cleave the C-I bond, producing CH and
3+
3
2
3
I , which may passivate iodine vacancies or reform MAI via reactions with NH I , ultimately restoring the
-
-
3
perovskite phase [147-149] .
Fast neutrons with energy > 10 MeV are generated through collisions between incoming plasma or cosmic
rays and the atmosphere’s constituents or materials comprising the spacecraft [150,151] . Paternò et al.
demonstrated MAPb(I Cl )-based p-i-n PSCs using a spallation neutron source at the ISIS Neutron and
x
3-x
Muon Source facility (Rutherford Appleton Laboratory, UK), simulating ~80 years of fast neutron exposure
equivalent to levels experienced on the ISS (1.5 × 10 particles cm s ) . The PSCs exhibited more stable PV
9
-2 -1 [152]
performance under neutron irradiation than under illumination, due to neutron bombardment .
[152]
This counterintuitive self-healing under radiation does not occur in conventional semiconductors, which
typically suffer cumulative damage under such conditions. Although applying radiation to enhance PSC
performance is impractical, this phenomenon highlights the unique radiation response of perovskites,
including a radiation-annealing threshold beyond which degradation begins. Identifying the optimal
radiation dose window that triggers beneficial defect healing without causing additional damage is currently
under investigation. By exploiting these unique properties, PSCs can be refreshed during service via natural
background radiation or controlled radiation. Overall, the self-healing of perovskites under radiation
provides potential for their long-term performance in space.

COMPARATIVE ANALYSIS WITH CONVENTIONAL SPACE PHOTOVOLTAIC TECHNOLOGIES
Radiation hardness and reliability
To withstand prolonged radiation exposure in space, solar cells require physical protection such as
cerium-doped glass [153] or fused silica [154] . Even with such shielding, ionization and lattice displacement
gradually degrade device performance and shorten PV lifetimes. PSCs exhibit exceptional intrinsic radiation
hardness compared with conventional silicon or III-V based photovoltaics [Figure 5A]. For instance, Si solar
cells typically lose 50%-80% of their output under proton irradiation at doses as low as ~1 × 10 p cm , due
-2
10
to defect formation . GaAs solar cells show similar vulnerability, with maximum power reduced by
[23]
50%-60% under fluences of ~ 1 × 10 e cm or 1 × 10 p cm -2[17] , and pronounced degradation of
16
12
-2
electroluminescence and V arising from nonradiative recombination centers induced by electron
oc
irradiation, even at fluence as low as 3 × 10 e cm -2[155] . By comparison, PSCs have maintained their initial
13
performance even under higher proton fluences reaching 1 × 10 p cm . This inherent radiation hardness
15
-2
suggests that PSCs could potentially operate in orbits or mission durations without the need for heavy
shielding, enabling lighter and simpler arrays with improved specific power. However, it is important to note
that the long-term reliability of PSCs remains unproven over multi-year timescales, especially compared with
the extensive flight heritage accumulated over decades for Si and III-V solar cells [156,157] . Therefore, extensive
qualification testing for PSCs is essential to validate that no unexpected failure modes arise, including