International Business Machines Corporation

Wei Liu

Yen-Fu Chen

Randolph Michael Forlenza

John W Dunsmoir

Messaoud Benantar

Sandra Juni Schlosser

David Brian Mitzi

Min Yuan

Techniques for improving energy conversion efficiency in photovoltaic devices are provided. In one aspect, an antimony (Sb)-doped film represented by the formula, CuInGaSbSeS, provided, wherein: 0&#x2266;x&#x2266;1, and ranges therebetween; 0&#x2266;y&#x2266;0.2, and ranges therebetween; 0.001&#x2266;z&#x2266;0.02, and ranges therebetween; and 0&#x2266;w&#x2266;2, and ranges therebetween. A photovoltaic device incorporating the Sb-doped CIGS film and a method for fabrication thereof are also provided.

Techniques for enhancing performance of photovoltaic devices

The present invention provides a photovoltaic device, such as, a solar cell, having a substrate and an absorber layer disposed on the substrate. The absorber layer includes a doped or undoped composition represented by the formula: CuInGaSeSwherein 0&#x2266;x&#x2266;1; 0&#x2266;y&#x2266;0.15 and 0&#x2266;z&#x2266;2; wherein the absorber layer is formed by a solution-based deposition process which includes the steps of contacting hydrazine and a source of Cu, a source of In, a source of Ga, a source of Se, and optionally a source of S, and further optionally a source of a dopant, under conditions sufficient to produce a homogeneous solution; coating the solution on the substrate to produce a coated substrate; and heating the coated substrate to produce the photovoltaic device. A photovoltaic device and a process for making same based on a hydrazinium-based chalcogenide precursor are also provided.

Photovoltaic device with solution-processed chalcogenide absorber layer

A Centralized Authentication & Authorization (CAA) system that facilitates secure communication between service clients and service providers. CAA comprises a Service Request Filter (SRF), a Service Client Authentication Program (SCAP), a Service Authorization Program (SAP), and an Authorization Database (ADB). The SRF intercepts service requests, extracts the service client's identifier from a digital certificate attached to the request, and stores the identifier in memory accessible to service providers. In the preferred embodiment, the SRF forwards the service request to a web service manager. The web service manager invokes SCAP. SCAP matches the identifier with a record stored in ADB. SAP queries ADB to determine if the service request is valid for the service client. If the service request is valid, SAP authorizes the service request and the appropriate service provider processes the service request.

Architecture and design for central authentication and authorization in an on-demand utility environment

Techniques for fabricating a photovoltaic device having a chalcopyrite absorber layer, such as a copper indium gallium selenide/sulfide (CIGSS) absorber layer, are provided. In one aspect, a method for fabricating a photovoltaic device is provided. The method includes the following steps. A precursor solution of metal chalcogenide dissolved in hydrazine or a hydrazine-like solvent is formed. Spray pyrolysis in an inert environment is used to deposit the precursor solution onto a substrate to form a metal chalcogenide layer on the substrate. A buffer layer is formed adjacent to a side of the metal chalcogenide layer opposite the substrate. A transparent conductive contact is formed adjacent to a side of the buffer layer opposite the metal chalcogenide layer.

Spray pyrolysis for large-scale production of chalcopyrite absorber layer in photovoltaic devices

A Centralized Authentication & Authorization (CAA) system that prevents unauthorized access to client data using a secure global hashtable residing in the application server in a web services environment. CAA comprises a Service Request Filter (SRF) and Security Program (SP). The SRF intercepts service requests, extracts the service client's identifier from a digital certificate attached to the request, and stores the identifier in memory accessible to service providers. The client identifier is secured by the SP using a key unique to the client identifier. When the web services manager requests the client identifier, the web services manager must present the key to the SP in order to access the client identifier. Thus, the present invention prevents a malicious user from attempting to obtain sensitive data within the application server once the malicious user has gained access past the firewall.

Growing community of inventors

Wexford, PA, United States of America

Wei Liu