Low Temperature Intensity Research Articles

Low-intensity low-temperature analysis of perovskite solar cells for deep space applications

Perovskite solar cells (PSCs) are studied in low-intensity low-temperature (LILT) conditions before and after low energy proton irradiation to characterize device performance at deep space mission-relevant light intensities and temperatures.

Low-intensity-low-temperature stability assessment of perovskite solar cells operating on simulated Martian surface conditions.

Immigration to Mars, which is expected to be powered mainly by photovoltaics, is one of the greatest dreams of humanity. However, the extreme temperature difference and high-energy cosmic radiation on the surface of Mars make it difficult for conventional photovoltaics to operate steadily over time. With their advantages of being lightweight, having a high irradiation tolerance, and an outstanding power conversion efficiency (PCE), perovskite solar cells (PSCs) have shown themselves to be a promising candidate for Martian applications. In this study, we simulated the low-intensity-low-temperature (LILT) environment of the Mars surface, and monitored the in situ device performance of PSCs. Surprisingly, the device PCE was not only maintained at a high level but was even improved slightly. Further investigation revealed that the self-healing effect of perovskites under LILT conditions could be attributed to the light-induced decomposition of the perovskite film and the β-phase perovskite recrystallization process at the perovskite/hole transport layer interface. Interfacial β-phase perovskites are stable at low temperatures, which can facilitate charge extraction and protect the perovskite bulk from long-term light damage. This study demonstrated the feasibility of PSCs and provides a reference for Martian applications.

Flexible Cu(In,Ga)Se$_{2}$ Solar Cells for Outer Planetary Missions: Investigation Under Low-Intensity Low-Temperature Conditions

Commercially available flexible Cu(In,Ga)Se $_{2}$ (CIGS) solar cells are assessed at low-intensity low-temperature (LILT) conditions consistent with those expected in the outer planetary systems of Saturn, Jupiter, and Mars. In these lower temperature environments, evidence of a photo-activated barrier is observed, which is attributed to the contribution of a parasitic barrier at the CIGS/CdS interface that is mediated by metastable defect complexes. However, this barrier only results in a small reduction in performance of the solar cells under LILT conditions. Irradiation with 1.5 MeV protons at very high fluence levels are also presented, resulting in defect-related degradation. However, subsequent self-healing under annealing conditions is also observed that offers potential for sustainable performance of these systems in space conditions.

Potential of High-Stability Perovskite Solar Cells for Low-Intensity–Low-Temperature (LILT) Outer Planetary Space Missions

Mixed-cation-based perovskite solar cells are investigated under conditions consistent with those found in orbit around Mars, Jupiter, and Saturn. Temperature dependent photoluminescence spectra sh...

Space degradation of 3J solar cells: I—Proton irradiation

AbstractTo understand the influence of proton irradiation on lattice‐matched GaInP/GaAs/Ge triple junction (TJ) solar cells under low intensity, low temperature (LILT) conditions, we investigated electrical behaviors of top, middle, and bottom component cells together with TJ cells under these conditions. Proton irradiations with energies of 1 MeV and fluences ranging from 2 × 1010 to 1.6 × 1012 cm−2 were performed at temperatures ranging from 100 to 300 K. Our study reveals that any of the 3 subcells can become the current limiting cell in the TJ cell, depending on temperature and fluence. In particular, remarkable degradation of the bottom cell at low temperature can make this subcell the current limiting in a TJ cell even for limited fluences. The results indicate that the defect distribution is non‐uniform for low temperature irradiation.

In Situ Irradiation and Measurement of Triple Junction Solar Cells at Low Intensity, Low Temperature (LILT) Conditions

The performance of triple junction InGaP/(In)GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">situ</i> at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation. Following irradiation at both temperatures and an extended room temperature anneal, quantum efficiency measurement suggests that the bulk of the remaining damage is in the (In)GaAs sub-cell.

Low-intensity low-temperature (LILT) measurements and coefficients on new photovoltaic structures

Low-intensity low-temperature (LILT) measurements and coefficients on new photovoltaic structures

Population differentiation in Australian Cardamine. III. Variation in germination response

Genetic variation in germination response was observed among a series of Cardamine populations whose habitats range from sea-level to 7200 ft in southern New South Wales. This variation was closely related to altitude. In populations from below 2000 ft, germination was inhibited at high temperatures, whereas those from above 5500 ft did not germinate at low temperatures. Among populations in which germination was inhibited at low temperatures the intensity of low temperature inhibition increased with increasing altitude. The adaptive significance of high and low temperature seed dormancy in these populations of Cardamine is discussed.