University of Delaware

Other

The United States of America As Represented by the Department of Energy

Brian E McCandless

Robert W Birkmire

Gregory M Hanket

Erten Eser

William N Shafarman

Thin films are produced by a method wherein a material is heated in a furnace placed inside a vacuum system. An inert gas is flown over/through the heated material. The vapors of the material are entrained in the carrier gas which is then directed onto a substrate heated to a temperature below that of the furnace temperature and placed in close proximity to the exit of the furnace.

Method for producing thin films

A chemical surface deposition process for forming an ultra-thin semiconducting film of Group IIB-VIA compounds onto a substrate. This process eliminates particulates formed by homogeneous reactions in bath, dramatically increases the utilization of Group IIB species, and results in the formation of a dense, adherent film for thin film solar cells. The process involves applying a pre-mixed liquid coating composition containing Group IIB and Group VIA ionic species onto a preheated substrate. Heat from the substrate causes a heterogeneous reaction between the Group IIB and VIA ionic species of the liquid coating composition, thus forming a solid reaction product film on the substrate surface.

Chemical surface deposition of ultra-thin semiconductors

An all dry method for producing solar cells is provided comprising first heat-annealing a II-VI semiconductor; enhancing the conductivity and grain size of the annealed layer; modifying the surface and depositing a tellurium layer onto the enhanced layer; and then depositing copper onto the tellurium layer so as to produce a copper tellurium compound on the layer.

All-vapor processing of p-type tellurium-containing II-VI semiconductor and ohmic contacts thereof

Semiconductor films and photovoltaic devices prepared therefrom are provided wherein the semiconductor films have a specular surface with a texture less than about 0.25 micron greater than the average planar film surface and wherein the semiconductor films are surface modified by exposing the surface to an aqueous solution of bromine containing an acid or salt and continuing such exposure for a time sufficient to etch the surface.

Process for levelling film surfaces and products thereof

Thin film photovoltaic solar cells are made by forming the cell structure from a number of layers including the contact layers and semiconductor layers. At least one of the semiconductor layers is a tellurium containing II-VI compound. After the structure is formed, it is heated to temperatures above 300.degree. C. and then rapidly cooled at rates greater than 10.degree. C./s. Cells comprising CdS and CdTe have increased fill factor when the fabrication process includes heating and rapid cooling.

Growing community of inventors

Elkton, MD, United States of America

Brian E McCandless