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Transverse Thermoelectric Voltage Detectors

IP.com Disclosure Number: IPCOM000084734D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

von Gutfeld, RJ: AUTHOR

Abstract

A thermoelectric detector for detection of light is described which uses multiple materials of appropriate thermopower to enhance periodic composition variation in the detector. This produces an increased sensitivity of the detectors.

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Transverse Thermoelectric Voltage Detectors

A thermoelectric detector for detection of light is described which uses multiple materials of appropriate thermopower to enhance periodic composition variation in the detector. This produces an increased sensitivity of the detectors.

The basic light detector is shown in U. S. 3,851,174. Columnar growth of the metal films used for the detectors is crucial for the thermoelectric voltage to be developed when light is incident on the film detector. This thermovoltage is due in part to the presence of slanted columns of materials which provide a periodic temperature variation across the film, as shown in Fig. 1A. A composition gradient in the transverse direction, together with the columnar growth, gives rise to a periodic temperature gradient along line B-B, as shown in Fig. 1B, which results in a transverse voltage originating from many microthermocouples, which are effectively connected in series.

To enhance the sensitivity of these two terminal detectors, two materials are evaporated sequentially to provide the detector. The first is a high-melting temperature material such as Mo, W, or Pt which is evaporated at an angle with respect to the substrate normal. Typically, an angle of 70 degrees is chosen. This first material is deposited to a thickness of the order of 1000 angstroms, in order to produce columns and regions between columns which remain nearly free of material. After this, a second material having a low-melting temperature is deposited at a direction along the substrate normal.

The purpose of this second evaporation is to partly fill in...