Triple-junction Space Solar Cells Research Articles

模拟太阳光与高空自然光条件下航天用三结砷化镓太阳电池光电性能测量对比

模拟太阳光与高空自然光条件下航天用三结砷化镓太阳电池光电性能测量对比

Study of the Impact Between a Triple Junction Space Solar Cell and the Antenna Integrated on Top of It

Solid and meshed patch antennas integrated on the cover glass of a commercial space solar cell were examined. The effect of the solar cell on the antenna was analyzed and validated. The impact of the antenna on the efficiency of the solar cell was quantified through experiments. It has been found that while the active semiconductor junction in a solar cell severely reduces the gain of the antenna in many space communication bands, the electrode lattice in the solar cell can potentially act as an isolation between the solar cell and the antenna, preventing the gain worsening. The effect of the lattice also promises a potential application in lab-grown solar cells such that one may carefully design the size and number of the electrodes to ensure the best gain for the integrated antenna. The main factor that impacts the efficiency of the solar cells was found to be the cover glass rather than the shadow from the antenna. These results can serve as design guidelines when integrating optically transparent antennas on solar panels of small satellites to reduce payload and to achieve reliable communication link. One may balance the selection of solar cells, cover glass, and antenna geometry to achieve the optimal link budget.

Improving Radiation Resistance of GaInP/GaInAs/Ge Triple-Junction Solar Cells Using GaInP Back-Surface Field in the Middle Subcell.

This paper studies the radiation resistance for GaInP/GaInAs/Ge triple-junction space solar cells with a GaInP back-surface field (BSF) in the GaInAs middle subcell compared with those with an AlGaAs BSF. The results show that the initial electrical performance is almost the same for both of them. However, the radiation resistance of the GaInP BSF cell was improved. After irradiation by 1 MeV electron beam with a cumulative dose of 1015 e/cm2, the Jsc declined by 4.73% and 6.61% for the GaInP BSF cell and the AlGaAs BSF cell, respectively; the efficiency degradation was 13.64% and 14.61% for the GaInP BSF cell and the AlGaAs BSF cell, respectively, leading to a reduced degradation level of 6%. The mechanism for GaInP BSF to improve the radiation resistance of GaInP/GaInAs/Ge triple-junction solar cells is also discussed in this work. Similar results were obtained when irradiation cumulative doses varied from 1 × 1014 e/cm2 to 1 × 1016 e/cm2.

Performace of Dilute Nitride Triple Junction Space Solar Cell Grown by MBE

Dilute nitride arsenide antimonide compounds offer widely tailorable band-gaps, ranging from 0.8 eV to 1.4 eV, for the development of lattice-matched multijunction solar cells with three or more junctions. Here we report on the performance of GaInP/GaAs/GaInNAsSb solar cell grown by molecular beam epitaxy. An efficiency of 27% under AM0 conditions is demonstrated. In addition, the cell was measured at different temperatures. The short circuit current density exhibited a temperature coefficient of 0.006 mA/cm 2 /°C while the corresponding slope for the open circuit voltage was −6.8 mV/°C. Further efficiency improvement, up to 32%, is projected by better current balancing and structural optimization.

Study of the electrical parameters degradation of GaAs sub-cells for triple junction space solar cells by computer simulation

In this paper, a theoretical study of the electrical parameters degradation of different n-type GaAs sub-cells for InGaP/GaAs/Ge triple junction solar cells irradiated with 1 and 5 MeV electrons has been performed by means of computer simulation. Effects of base carrier concentration upon the maximum power point, short-circuit current, open circuit voltage, diffusion current, recombination current and series resistance of these devices have been researched using the displacement damage dose method, the one-dimensional PC1D device modeling program and a home-made numerical code based on genetic algorithms. The radiative recombination lifetime, damage constant for minority-carrier lifetime and carrier removal rate models for GaAs sub-cells have been used in the simulations. An analytical model has been proposed, which is useful to describe the radiation-induced degradation of diffusion current, recombination current and series resistance. Results obtained in this work can be used to predict the radiation resistance of solar cells over a wide range of energies.

Computational analysis of the maximum power point for GaAs sub-cells in InGaP/GaAs/Ge triple-junction space solar cells

The radiation resistance in InGaP/GaAs/Ge triple-junction solar cells is limited by that of the middle GaAs sub-cell. In this work, the electrical performance degradation of different GaAs sub-cells under 1 MeV electron irradiation at fluences below 4 × 1015 cm−2 has been analyzed by means of a computer simulation. The numerical simulations have been carried out using the one-dimensional device modeling program PC1D. The effects of the base and emitter carrier concentrations of the p- and n-type GaAs structures on the maximum power point have been researched using a radiative recombination lifetime, a damage constant for the minority carrier lifetime and carrier removal rate models. An analytical model has been proposed, which is useful to either determine the maximum exposure time or select the appropriate device in order to ensure that the electrical parameters of different GaAs sub-cells will have a satisfactory response to radiation since they will be kept above 80% with respect to the non-irradiated values.

Electroluminescence and Photoluminescence Characterization of Multijunction Solar Cells

A combined electroluminescence and photoluminescence setup for a fast, nondestructive, and high-resolution characterization of large-area lattice matched GaInP <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Ga(In)As/Ge triple-junction space solar cells was developed. In contrast with electroluminescence, where coupling effects between the subcells appear, all subcells can be analyzed independently in photoluminescence imaging, using three monochromatic light sources. This will be demonstrated by way of example for a partly irradiated cell. Alternatively, electroluminescence combined with simulation program with integrated circuit emphasis network simulations constitutes a powerful tool to extract quantitative information despite the coupling effects. Sheet resistances and shunts in individual subcells can be accurately modeled with this method.

Adjusted NIEL calculations for estimating proton-induced degradation of GaInP/GaAs/Ge space solar cells

The non-ionizing energy loss (NIEL) values for protons in solar cells should be modified by taking into account the distribution of the Bragg damage peak in the active region to calculate the corresponding displacement damage dose. In this paper, based upon a thin target approximation, a new approach is presented to modify NIEL values for protons on a GaAs sub-cell. Adjusted NIEL values can be used to estimate the degradation induced by protons on GaInP/GaAs/Ge triple-junction space solar cells.

Modeling of degradation behavior of InGaP/GaAs/Ge triple-junction space solar cell exposed to charged particles

Degradation modeling of InGaP/GaAs/Ge triple-junction (3J) space solar cells, which are exposed to charged particles (protons and electrons), is introduced using a one-dimensional optical device simulator: PC1D. The proposed method can reproduce the electrical degradation of 3J solar cells from fitting the external quantum efficiencies for subcells. In this modeling, carrier removal rate of base layer (RC) and damage coefficient of minority carrier diffusion length (KL) in each subcell are considered as radiation degradation parameters. Nonionizing energy loss (NIEL) analysis for both radiation degradation parameters is discussed. The radiation degradation of a 3J solar cell can be predicted from the results of degradation level in the each subcell estimated from correlativity between NIEL and both radiation degradation parameters.

ESD Ground Testing of Triple-Junction Space Solar Cells with Monolithic Diodes

High-efficiency triple-junction (TJ) solar cells with monolithic diodes (MD) are being used for recent spacecraft solar arrays. Because the cell-to-cell inter-connector is usually connected on the MD pad, studying the effects of electrostatic discharge (ESD) on MD is necessary. Laboratory testing of two types of MD functions revealed that the weaker design was damaged by an energy discharge of 0.8J. With an external circuit simulating flight solar array, however, discharge as large as 9.3J didn't destroy the solar cell. Based on the test results, it was concluded that MD solar cells have sufficient resistance against ESD in orbit.

Activity and current status of R&amp;D on space solar cells in Japan

Japan's Research and Development (R&D) activities on high-performance III–V compound space solar cells are presented. Studies of new CuInGaSe2 thin-film terrestrial solar cells for space applications are also discussed. Performance and radiation characteristics of a newly developed InGaP/GaAs/Ge triple-junction space solar cell, including radiation response, results of a flight demonstration test of InGaP/GaAs dual-junction solar cells and CuInGaSe2 thin-film solar cells, and radiation response of three component sub-cells are explained. This study confirms superior radiation tolerance of InGaP/GaAs dual-junction cells and CuInGaSe2 thin-film cells by space flight experiments. Copyright © 2005 John Wiley & Sons, Ltd.

MOVPE growth of lattice-mismatched Al 0.88In 0.12As on GaAs (1 0 0) for space solar cell applications

We report, for the first time, the growth and characterization of lattice-mismatched Al 0.88In 0.12As on GaAs (1 0 0) as part of a program to develop a high-efficiency, triple-junction space solar cell. The expected practical efficiency of this cell is 31%. The proposed triple-junction cell consists of a 2.1 -eV Al 0.88In 0.12As top cell, a 1.6 -eV In 0.48Ga 0.52As 0.23P 0.77 middle cell, and a 1.2 -eV In 0.13Ga 0.87As bottom cell. The Al 0.88In 0.12As layers were grown on GaAs (1 0 0) wafers cut 6° off-axis, using metal organic precursors trimethylaluminum, trimethylindium and the hydride arsine in a horizontal, reduced-pressure metal organic vapor-phase epitaxy (MOVPE) reactor. Crystalline quality was evaluated through triple-axis X-ray diffractometry. Reciprocal lattice mapping showed that the Al 0.88In 0.12As layers were relaxed to a large extent, and were of high crystalline quality. Doping was performed using silane (n-type) and diethylzinc (p-type). Secondary ion mass spectrometry (SIMS) and electrochemical C– V profiling showed that it was possible to obtain abrupt doping profiles to the levels required for solar cell fabrication. Details of these results and those of dislocation density measurement using transmission electron microscopy (TEM) are described in this paper.