Photovoltaic devices and method of making

a photovoltaic device and photovoltaic technology, applied in the field of photovoltaic devices, can solve the problems of cdte, photovoltaic devices typically demonstrate relatively low power conversion efficiency, and current cdte devices may have significant recombination of electron-hole pairs

Inactive Publication Date: 2014-12-25
FIRST SOLAR INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This configuration leads to increased open circuit voltage and short circuit current densities, improving the overall efficiency of the photovoltaic device by reducing leakage current density and allowing more light to pass through to the absorber layer.

Problems solved by technology

Cadmium telluride (CdTe)-based photovoltaic devices typically demonstrate relatively low power conversion efficiencies, which may be attributed to a relatively low open circuit voltage (Voc) in relation to the band gap of the material which is due, in part, to the low effective carrier concentration and short minority carrier lifetime in CdTe.
However, current CdTe devices may have significant recombination of electron-hole pairs at the front interface between CdS and CdTe.
Furthermore, thinner CdTe may also lead to recombination of electron hole-hole pairs at the back contact of the CdTe photovoltaic device.

Method used

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  • Photovoltaic devices and method of making
  • Photovoltaic devices and method of making
  • Photovoltaic devices and method of making

Examples

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Embodiment Construction

[0028]As discussed in detail below, some of the embodiments of the invention provide improved interfaces in a photovoltaic device. In some embodiments, an improved front interface is provided. In certain exemplary embodiments, an improved front interface includes a porous layer disposed between a front TCO (transparent conductive oxide) layer and an absorber layer (for example, CdTe). The pores in the porous layer are filled with a window layer material (for example, CdS) to form a patterned window layer. Accordingly, in such embodiments, the patterned window layer includes discontinuous regions of window material that may function as point contacts for charge collection. In contrast to a continuous layer of window layer material in contact with the absorber layer, a patterned window layer may be advantageously used to minimize interface recombination, in accordance with one embodiment of the invention. Further, the reduced contact area between the window and absorber layers and the...

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Abstract

In one aspect of the present invention, a photovoltaic device is provided. The photovoltaic device includes a transparent layer; a first porous layer disposed on the transparent layer, wherein the first porous layer comprises a plurality of pores extending through a thickness of the first porous layer; a first semiconductor material disposed in the plurality of pores to form a patterned first semiconductor layer; and a second semiconductor layer disposed on the first porous layer and the patterned first semiconductor layer, wherein the patterned first semiconductor layer is substantially transparent. Method of making a photovoltaic device is also provided.

Description

BACKGROUND[0001]The invention generally relates to photovoltaic devices. More particularly, the invention relates to improved interfaces for photovoltaic devices.[0002]Thin film solar cells or photovoltaic devices typically include a plurality of semiconductor layers disposed on a transparent substrate, wherein one layer serves as a window layer and a second layer serves as an absorber layer. The window layer allows the penetration of solar radiation to the absorber layer, where the optical energy is converted to usable electrical energy. Cadmium telluride / cadmium sulfide (CdTe / CdS) heterojunction-based photovoltaic cells are one such example of thin film solar cells.[0003]Cadmium telluride (CdTe)-based photovoltaic devices typically demonstrate relatively low power conversion efficiencies, which may be attributed to a relatively low open circuit voltage (Voc) in relation to the band gap of the material which is due, in part, to the low effective carrier concentration and short mino...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): H01L31/0236H01L31/18
CPCH01L31/02363H01L31/1832H01L31/1884H01L31/073Y02E10/543H01L31/022425H01L31/0296H01L31/03529Y02P70/50
InventorKOREVAAR, BASTIAAN ARIEWHITNEY, RENEE MARYAHMAD, FAISAL RAZI
OwnerFIRST SOLAR INC