摘要:

DayStar Technologies is developing a PV module technology using low-level concentration (2–8 suns) that can package existing industry cell materials into a lower cost/higher value product suitable for both low-power (10W) solar lantern and 1-KW and greater power generation applications. Cell materials incorporated to date includeCu(In,&hthinsp;Ga)Se2(CIGS),a-Si, and c-Si. The use of thin-film cell materials in a concentrator application is the first of its kind. The performance and reliability of CIGS and a-Si under concentration has been demonstrated. The efficacy of the proprietary optics developed by DayStar has been demonstrated. Cell integration and subsequent mating to optics has proven to be nearly lossless. A 7.2&percent; active-area CIGS-based mini-module has been measured. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57906

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

AstroPower is developing an advanced thin-silicon-based, photovoltaic module product. A low-cost monolithic interconnected device is being integrated into a module that combines the design and process features of advanced light trapped, thin-silicon solar cells. This advanced product incorporates a low-cost substrate, a nominally 50-&mgr;m thick grown silicon layer with minority carrier diffusion lengths exceeding the active layer thickness, light trapping due to back-surface reflection, and back-surface passivation. The thin silicon layer enables high solar cell performance and can lead to a module conversion efficiency as high as 19&percent;. These performance design features, combined with low-cost manufacturing using relatively low-cost capital equipment, continuous processing and a low-cost substrate, will lead to high-performance, low-cost photovoltaic panels. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57979

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

In 1995, the NREL/Department of Energy (DOE) National Photovoltaics Program funded seven Historically Black Colleges and Universities (HBCUs) in its HBCU Photovoltaic Research Associates Program for a period of three years. The program’s purpose is to advance HBCU undergraduate knowledge of photovoltaics, primarily as a result of research investigations performed, and to encourage students to pursue careers in photovoltaics. This paper presents results from PV projects ranging from fundamental materials research on PV materials to field projects of PV systems. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57980

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Photovoltaics (PV) technology has definite environmental advantages over competing electricity generation technologies, and so far these advantages have driven market penetration. The PV industry follows a pro-active approach to preserve its safe and environmentally friendly nature. Industrial ecology considerations raise the issue of what to do with the PV modules at the end of their useful life. One option is recycling. This paper discusses the value of proactive recycling and compares several alternatives. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57908

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

A brief review of performance-limiting processes in a commercial solar cell fabricated on low-cost substrate is given. Higher efficiencies require effective gettering of precipitated impurities present at the defect clusters, and improved cell and process designs. Overcoming these limitations is expected to lead to 18&percent;–20&percent; cell efficiencies. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57981

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

This paper summarizes recent progress in the development of back-contact crystalline-silicon (c-Si) solar cells and modules at Sandia National Laboratories. Back-contact cells have potentially improved efficiencies through the elimination of grid obscuration and allow for significant simplifications in the module assembly process. Optimization of the process sequence has improved the efficiency of our back-contact cell (“emitter wrap through”) from around 12&percent; to near 17&percent; in the past 12 months. In addition, recent theoretical work has elucidated the device physics of emitter wrap-through cells. Finally, improvements in the assembly process using back-contact cells are described. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57982

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Rapid and potentially low-cost process techniques are analyzed and applied toward the fabrication of high-efficiency Si solar cells. First, a high quality screen-printed (SP) contact methodology is developed that results in fill factors of 0.785-0.790 on monocrystalline Si. Next, aluminum back surface field (Al-BSF) formation is studied in detail to establish the process conditions that result in optimal BSF action. Screen-printing of Al conductor paste and rapid thermal processing (RTP) are integrated into the BSF procedure, and effective recombination velocities(Seff)as low as 200 cm/s are demonstrated on 2.3 &OHgr;-cm Si with this RTP SP Al-BSF process. A novel passivation scheme consisting of a dielectric stack (plasma silicon nitride on top of a rapid thermal oxide) is developed to reduce the surface recombination velocity (S) to ≈10 cm/s at the 1.3 &OHgr;-cm Si surface. The important feature of this stack passivation scheme is its ability to withstand a high-temperature anneal (700–850&hthinsp;°C) without degradation in S. This feature is critical for most current commercial processes that utilize SP contact firing. Finally, the individual processes are integrated to form high-efficiency, manufacturable devices. Solar cell efficiencies of 17&percent; and >19&percent; are achieved on FZ Si with SP and evaporated (photolithography) contacts, respectively. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57909

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Growth in world-wide demand for silicon (Si) photovoltaics (PV) and a short-fall in the traditional supplies of Si into the PV industry call for renewed interest in determining the quantities of Si required per megawatt, the specifications for solar grade Si feedstock, and the technologies for producing such material. An ample, dedicated and consistent solar Si supply independent of the Si electronics industry is recommended. Low cost (less than $20 per kg) solar Si feedstock is part of the technology portfolio for achieving PV products in the $1 per watt range. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57983

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

Three- and four-junction III-V devices are proposed for ultrahigh-efficiency solar cells using a new 1-eV material lattice-matched to GaAs, namely, GaInNAs. We demonstrate working prototypes of a GaInNAs-based solar cell lattice-matched to GaAs with photoresponse down to 1 eV. Under the AM1.5 direct spectrum with all the light higher in energy than the GaAs band gap filtered out, the prototypes grown with base doping of about1017&hthinsp;cm−3have open-circuit voltages ranging from 0.35 to 0.44 V, short-circuit current densities of 1.8 mA/cm2, and fill factors from 61&percent; to 66&percent;. To improve on the current record-efficiency tandem GaInP/GaAs solar cell by adding a GaInNAs junction, the short-circuit current density of this 1-eV cell must be significantly increased. Because these low short-circuit current densities are due to short diffusion lengths, we have demonstrated a depletion-width-enhanced variation of one of the prototype devices that trades off decreased voltage for increased photocurrent, with a short-circuit current density of 7.4 mA/cm2and an open-circuit voltage of 0.28 V. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57984

出版商:AIP    

年代:1999

数据来源: AIP

摘要:

GaInP/GaAs cells invented and developed at NREL have achieved world-record efficiencies. We estimate that their production for space applications has grown to >$100 million/yr. Approximately 300 MW/yr of 1000X terrestrial concentrator cells could be fabricated with the existing manufacturing capacity at a cost of about 21¢/Wp. A resurgence of interest in terrestrial PV concentrators, together with the strength of the III-V space-solar-cell industry, indicate that III-V cells are also attractive for terrestrial applications. ©1999 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.57985

出版商:AIP    

年代:1999

数据来源: AIP