摘要:

AbstractThermodynamic equilibration kinetics of phosphorus‐ and boron‐doped hydrogenated amorphous silicon (a‐Si:H) are explored using dark conductivity measurements. the equilibration kinetics of phorphorus‐ and boron‐doped a‐Si:H are different and there is a strong dependence on the deposition temperature (Ts). Small variations in temperature of the semiconductor cause variations in active dopant concentration, which affects the conductivity. the transformation of phorphorus into the electronically active phase (activation) follows a stretched exponential time dependence with a temperature‐independent dispersion parameter, β, of 0.85, whereas the transformation into the electronically passive bonding configuration (passivation) is also a stretched exponential but with β ⩽ 0.8. the kinetics of boron metastability are similarly a stretched exponential, but with equal β values for activation and passivation. the time constant, τ, to achieve equilibrium for both transformations is thermally activated with energies Eact∽ 1.1 eV for phosphorus and boron. an increase in Tsleads to an increase of Eact. the data are discussed and interpreted based on the hyd

ISSN:1062-7995    

DOI:10.1002/pip.4670010402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe steady‐state photocarrier grating technique is analysed with respect to deviations from local charge neutrality. We present a generalized expression for the normalized photoresponse β as a function of the grating period as well as of the external electric field; the transport is characterized in the sense of bipolar and ambipolar, diffusion and drift displacement, respectively. Experimental data for undoped a‐Si: H, especially the variation of the β coefficient with the external electric field, are discussed and fitted by the generalized equation. the effective dielectric relaxation time, which takes the trapped photogenerated majority carriers into account, is found to be responsible for ambipolar transport in undoped a‐Si: H in the low electric field regime. Further, the μτ‐products of electrons and holes in a‐Si1‐xGex: H alloys are deduced experimentally. the low‐gap alloys are an appropriate candidate for photovol

ISSN:1062-7995    

DOI:10.1002/pip.4670010403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractSolution grorwth of CdS on SnO2‐coated glass with subsequent heat treatments is known to produce stoichiometric CdS thin films with characteristic thicknesses of about 1000 Å. We show that heating solution‐grown CdS thin films in a nitrogen atmosphere to ⩾ 450° C results in sulphur loss. Heating to 550°C leads to a 50% loss of sulphur, leaving the entire 1000‐A CdS thin film with a concentration of about 75 at.% Cd and 25 at.% S. However, dipping the CdS thin films in a CdCl2solution prior to heating coats the CdS, leaving a CdCl2layer that acts as a protective coating and prohibits the loss of sulphur. Cadmium sulphide thin films dipped in a CdCl2solution and then heated to 550°C are sto

ISSN:1062-7995    

DOI:10.1002/pip.4670010404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA battery model is proposed as a tool to simulate and optimize photovoltaic (PV) / storage systems. the normalized form of the equations with respect to the battery capacity allows us to generalize its use for any type and size of lead‐acid batteries.The validity of this model to represent the battery voltage evolution during charge, overcharge and discharge processes and to predict the performance of solar systems under different operational conditions is analysed. Moreover, the battery efficiency losses are presented as a function of the upper regulation thresholds of the charge controllers and the size of the array and storage systems in a domestic application in the climate of Madri

ISSN:1062-7995    

DOI:10.1002/pip.4670010405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA bifacial photovoltaic module can collect not only the light falling directly on its front but also light incident on its rear after reflection from natural surroundings, called the albedo reflection, and light scattered from the sky itself. the benefits of such bifacial response are analysed by modifying a standard computer photovoltaic simulation software package (PVFORM version 3.3). Results obtained from computer simulation and field experiments show that, without any special features, there is about a 20% increase in the total annual energy generated by a bifacial panel compared to a monofacial panel. There are also summer peaks caused by the morning and evening light falling directly on the rear side of the panel. This means that the bifacial panel allows extended operation during summer. There is also a slightly smaller reduction in relative output power for the bifacial module on cloudy days.

ISSN:1062-7995    

DOI:10.1002/pip.4670010406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper presents an analysis of an optimal decentralized mix of photovoltaics, biogas generation and biomass gasifier generation, to meet the electrical energy demand of typical villages in the North Indian plains. the optimal mix preserves existing patterns of fertilizer application and cooking and also corresponds to minimum cost. Survey data for four villages have been used for a numerical appreciation of the results. It is seen that the optimal energy strategy consists of meeting as much demand as possible by biogas generators using dung and meeting the rest of the demand by an optimal combination of biomius gasifier generation and photovoltaics. the cost of electrical energy with such decentralized systems lies between Rs. 2.2 per k Wh and Rs. 8.9 per k Wh for different villages (US $1 = Rs. 30). It is seen that locally availble fuel (dung and agricultural waste) is insufficient for electrical generation and the balance has to be met by photovoltaics. Rising electrical demand in coming years means that pliotovoltaics will be an increasingly important component of such optimal systems.

ISSN:1062-7995    

DOI:10.1002/pip.4670010407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThirty‐four university teams raced their solar‐powered cars from Texas to Minnesota during the week of the summer solstice, 20‐26 June 1993. the event, called Sunrayce 93, was a dazzling display of creativity and ingenuity by some of the brightest students in North America. Organized by the United States Department of Energy as an educational programme for college‐level science and engineering students, the race also serves to introduce the public to photovoltaics, electric vehicles and energy eff

ISSN:1062-7995    

DOI:10.1002/pip.4670010408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1062-7995    

DOI:10.1002/pip.4670010409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1062-7995    

DOI:10.1002/pip.4670010410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:1062-7995    

DOI:10.1002/pip.4670010411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY