摘要:

This paper describes the characteristics of a 1 cm2solar cell using the structure ZnO/CdZnS/CuInGaSe2which has given an AM1.5G efficiency of 13.1%. The characteristics of each layer of the device are discussed, current‐voltage and quantum efficiency characteristics presented, and the reasons for the improved performance compared to previous high efficiency cells identified. Possible further improvements are discussed.

ISSN:0094-243X    

DOI:10.1063/1.42908

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

A novel method has been developed for the preparation of copper‐indium‐diselenide (CIS) thin films. The method comprises of elemental deposition of Cu, In, and Se layers followed by a CIS compound formation process which does not involve any H2Se gas. The process has led to the formation ofp‐type CIS films which have proper stoichiometry and grain sizes on the order of 1 &mgr;m. The best solar cell fabricated on this material had an active area conversion efficiency of 10.2% withVoc=0.427 V,Jsc=37.41 mA/cm2, and FF=0.641.

ISSN:0094-243X    

DOI:10.1063/1.42909

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

A process compatible with large scale manufacturing was developed to prepare polycrystalline thin films of CuInSe2for photovoltaic applications. The technique involves the deposition of a multilayer (Cu‐In)nstack by magnetron sputtering onto Mo‐coated soda lime glass, followed by selenization by a method not requiring H2Se. The new selenization process involves the exposure of the annealed Cu‐In stack to Se while simultaneously ramping in temperature. The process results in high quality CuInSe2crystal growth with automatic convergence of valence stoichiometry. Properties of resulting films and heterojunction devices are described, with solar cell efficiencies of 8.9% so far having been attained.

ISSN:0094-243X    

DOI:10.1063/1.42910

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

A key issue for photovoltaics (PV), both in terrestrial and future space applications, isproducibility, particularly for applications utilizing a large volume of PV. Among the concerns for fabrication of polycrystalline thin‐film photovoltaics, such as copper‐indium‐diselenide (CIS) and cadmium‐telluride (CdTe), are production volume, which translates directly related to cost, and minimization of waste. Both the rotating cylindrical magnetron (C‐MagTM) and pulsed electrodeposition have tremendous potential for the fabrication of polycrystalline thin‐film photovoltaics due to scaleability, efficient utilization of source materials and inherently higher deposition rates. In the case of sputtering, the unique geometry of the C‐MagTMfacilitates innovative cosputtering and reactive sputtering that could lead to greater throughput, reduced health and safety risks, and ultimately lower fabrication cost. For pulsed electrodeposition, the films appear to be more tightly adherent and deposited at an enhanced rate when compared to conventional DC electrodeposition. This paper addresses Martin Marietta’s investigation into innovative sputtering techniques and pulsed electrodeposition with a near‐term goal of 930 cm2(1 ft2) monolithically‐integrated CIS and CdTe submodules.

ISSN:0094-243X    

DOI:10.1063/1.42911

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We have developed a sequential process for the fabrication of enhanced‐grain thin‐film CuInSe2‐based photovoltaic devices. In this process, exact control of the composition during fabrication is not necessary. Analysis of the film structures suggests enhanced grain size, transport, and photoconductivity. Device structures vary from one‐sided heterojunctions to buried homojunctions where the window layer is not required for photo‐response. We have also developed a fabrication process that incorporates variable elemental fluxes and flux ratios, and a substrate temperature of 550 °C. Preliminary results include a fill‐factor of 75%, a diode factor of 1.2, and enhanced spectral response in the near‐infrared region. We present an update on this work and attempt to describe the relationship between the growth dynamics and the resultant material and device performance. The results suggest new approaches to the fabrication of high efficiency CuInSe2‐based solar cells.

ISSN:0094-243X    

DOI:10.1063/1.42913

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Thin‐film Copper Indium Diselenide has been deposited using a two‐step process with solid selenium as the Se source rather than H2Se. Film properties are strongly influenced by the substrate. Borosilicate glass produces more nucleation sites and smoother thin‐films, while 1000 A˚ films deposited on soda lime glass may exhibit disconnectedness. Electronic properties are similarly affected, particularly mobilities. Using MOSFET devices as analytical tools electron channel mobilities of up to 45 cm2/Vs have been measured. Preliminary results from thin‐film transistor dynamics indicate that traps with a trapping time of about 10 seconds are controlling surface properties and limiting solar cell performance.

ISSN:0094-243X    

DOI:10.1063/1.42914

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Large‐grained copper indium diselenide crystal growth by computer‐controlled high‐pressure liquid‐encapsulated directional solidification is presented. A supply of good quality angle crystals is essential to characterization of the fundamental material properties. [AIP]

ISSN:0094-243X    

DOI:10.1063/1.42915

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Analysis of thin film polycrystalline heterojunction solar cells explains how minority carrier recombination at the metallurgical interface and at grain boundaries can be greatly reduced by the proper doping of the window and absorber layers. When this is done, these devices exhibit the high quantum efficiencies andJsc’s measured in high efficiency CdTe and CuInSe2based solar cells. The analysis also shows that any quantitative modeling of these devices which relates the device performance to the bulk electronic properties of the material must consider the additional geometric dimension introduced by the polycrystallinity. Additional analysis and measurements show that the present solar cells are limited by the magnitude of the diode current which appears to be caused by recombination in the space charge region.

ISSN:0094-243X    

DOI:10.1063/1.42916

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

Developing an efficient commercial scale process for fabricating large area polycrystalline thin film solar cells from a research process requires detailed understanding of the individual steps in making the solar cell and their relationship to device performance and reliability. In this paper, the complexities involved in characterizing a process are demonstrated with results from our research program on CuInSe2and CdTe processes.

ISSN:0094-243X    

DOI:10.1063/1.42917

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The voltage of both CuInSe2and CdTe cells continues to increase after either the onset of illumination or if an illuminated cell is switched from closed to open circuit conditions. The magnitude of the transient voltage effect is typically 10 to 50 mV. Time constants span several decades, 10−4to 10+4s, and are shorter at higher temperatures. The voltage shift is essentially the same at open‐circuit and operating voltages. It depends primarily on the voltage history, not the illumination history, of the cell. The time‐dependent voltage has implications for both the device physics of cells and the interpretation of pulse‐simulator data.

ISSN:0094-243X    

DOI:10.1063/1.42918

出版商:AIP    

年代:1992

数据来源: AIP