Solar Cells最新文献

A stepped sinewave full-bridge inverter was analysed theoretically to determine its optimum working conditions, its minimum number of components, and characteristic of its constituent components and control circuit of its power switches.

A computer program, written in FORTRAN-77, was developed to analyse this inverter circuit. The program prompts for input data such as the characteristics of the power and control circuit elements, the output fundamental frequency, and the number of available batteries and their voltage. The output of the program is designed to give the optimum stair widths, the loss, the harmonic and the total efficiency, the harmonic distortion, the sensitivity of the efficiency and fundamental voltage to the variation in stair width, and the energy withdrawal from each battery for the power switches controlling the circuit. Interesting design data for this circuit were also obtained.

In July 1990, 32 North American university teams gathered in Orlando, FL to compete in GM Sunrayce USA, a 1650 mile transcontinental race of solar powered cars. Using only sunlight for power, the cars had to travel through eight states over eleven days before reaching the finish line in Detroit, MI. Created as a student competition to strengthen hands-on science and engineering skills, Sunrayce was a triumph of higher learning. Students were motivated to learn skills and excel at challenges they never thought possible. Their hard work, creativity and innovation surpassed everyone's expectations. What started out as a race of students ended as a race of scientists and engineers better prepared for their nature.

The prize for the three winners of Sunrayce was an all expenses paid trip to compete in the 1990 World Solar Challenge (WSC) in Australia. The WSC is a 1870 mile solar car race across the Australian outback. This year's event had 36 competitors from around the world, including eleven entries from Japan, eight from the U.S.A., and five from Europe. In total, 62 different solar racing teams competed in the two events in 1990.

Both events are described in detail in this paper. Vehicle specifications, race results and day-by-day descriptions of how the race developed are provided. Technical details of the three winning teams in GM Sunrayce USA are given in individual design reports written by the teams and following this paper. Pictures and summaries of each Sunrayce vehicle are given in Appendix A, which follows the design reports.

In November 1987, the first World Solar Challenge took place, a 3000 km (1860 miles) transcontinental solar powered vehicle race from Darwin to Adelaide across the Australian Outback. The race, held every three years, featured entries from various countries, including Switzerland, Japan, Australia, and the United States. The winning car, General Motors' Sunraycer, finished 970 km (600 miles) in front of its nearest competitor. Based on this outstanding performance, General Motors decided not to return to Australia in 1990, but to instead sponsor a solar car race of its own and send the top three finishers to the international competition. GM Sunrayce USA featured 32 cars from top engineering colleges throughout North America and took place from Florida to Michigan, covering 2660 km (1650 miles) during July 1990.

In 1987, the General Motors experimental vehicle “Sunraycer” won the inaugural World Solar Challenge race in grand form. Powered only by energy from the sun, this rolling showcase of high technology sprinted across the Australian continent, winning by two days over its nearest competitor at an average speed of 41.6 miles per hour. To encourage additional practical research in the field of solar vehicles, General Motors, the U.S. Department of Energy, and the Society of Automotive Engineers sponsored a solar car race in 1990 called the GM Sunrayce USA.

The Vehicle Research Institute at Western Washington University designed and constructed the Viking XX Solar Race Vehicle to compete in GM Sunrayce USA. In this event, cars from 32 universities race from Orlando, FL to Detroit, MI, with the sun being the only energy source used to propel the vehicles. Viking XX is an advanced composite, monocoque chassis, two-person, solar powered vehicle that can run in either direction. The solar panel is composed of terrestrial grade solar cells. The energy produced by the array is stored in silver zinc batteries, which in turn power a 20 hp brushless, rare-earth, permanent magnet, d.c. motor located on the main drive wheel in the center of the drivers' pod. Two wheels mounted in the battery pod counter steer one another so that the car has a very tight turning radius. This paper is a concise description of the research, testing and design of the Viking XX solar race vehicle.

A review of the deep-level defects observed in both electron- and proton-irradiated GaAs solar cells is presented. Studies of the effects of periodic and continuouss thermal annealing on the radiation-induced electron and hole traps and the recombination parameters in GaAs solar cells were made for a wide range of electron and proton energies, fluence, annealing temperature and annealing time. A refined model for numerical simulations of the displacement damage was developed for computing the defect density and the cell parameters in the electron- and proton-irradiated GaAs solar cells. excellent agreement was obtained between the calculated values and the experimental data for the proton-irradiated GaAs solar cells.

The effects of radiation on InP solar cells is reviewed. Included are: a performance overview comparing InP, GaAs and silicon cells under laboratory irradiations, space flight data, defect studies using both electron paramagnetic resonance and deep level transient spectroscopy, carrier removal, thermal and minority carrier injection annealing and lifetime and diffusion length radiation damage coefficients. A discussion of the primary reason for the superior performance, under irradiation, of InP solar cells is followed by an exposition of the barrier problems requiring solution before InP can be considered for widespread use in space.

Copper indium diselenide, cadmium telluride and amorphous silicon alloy solar cells have achieved noteworthy performance and are currently being investigated for space power applications. Cadmium sulphide cells had been the subject of considerable effort but are no longer considered for space applications. This article presents a review of what is known about the radiation-induced degradation of thin-film solar cells in space. Experimental investigations of electron and proton irradiation of cadmium sulphide, copper indium diselenide, cadmium telluride and amorphous silicon alloy cells are reviewed. Damage mechanisms and radiation-induced defect generation and passivation in the amorphous silicon alloy cell are discussed in detail owing to the greater amount of experimental data available.

A review of three promising defect characterization techniques is presented. It is shown how deep level transient spectroscopy can provide information about energy level, density and capture cross-section of electrically active defects produced by irradiation. Both Doppler and lifetime positron annihilation spectroscopies are reviewed to show how configuration of radiation-induced defects can be identified by these techniques. Finally, the electron paramagnetic resonance technique is briefly reviewed and its usefulness is demonstrated by describing the investigations of radiation-induced Si-A center and positively charged silicon vacancy defect.

n-Type CuInSe₂ thin films obtained by electrodeposition from a chloride bath containing SeO₂ and annealed at different temperatures in N₂ plus either 5% H₂ or a few parts per million O₂ were investigated to discover their photoelectrochemical and electrolyte electroreflectance behaviour. The fundamental parameters of the thin film-polysulphide electrolyte junction were determined and the performance and stability of the films were examined in photoelectrochemical cells. Finally, a point-by-point surface investigation with both a white light spot and a thin laser beam was performed, showing the non-uniform photoelectrochemical and electrolyte electroreflectance response of the films which could be related to inhomogeneous dopant distribution.