Browse Prior Art Database

Adjustable Long Wavelength Photo-Detector

IP.com Disclosure Number: IPCOM000036541D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Brodsky, MH: AUTHOR [+3]

Abstract

A technique is described whereby a high-efficiency, high-speed adjustable long wavelength photo-detector can be integrated with VLSI signals for optical fiber communication applications.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 56% of the total text.

Page 1 of 2

Adjustable Long Wavelength Photo-Detector

A technique is described whereby a high-efficiency, high-speed adjustable long wavelength photo-detector can be integrated with VLSI signals for optical fiber communication applications.

The adjustable long wavelength photo-detector is designed to provide adjustable long wavelength photo-detection capability by utilizing superlattice periodicity and relative doping. It provides a short transit time and has the potential for use as a high-efficiency solar cell, due to extended wavelength conversion capabilities. Carrier separation in the layers provides long lifetime, high-gain photo-detector applications.

The long wavelength photo-detector is fabricated with periodically doped layers (p-i-p-i), such that if the net doping level difference between the adjacent layers is sufficiently large, the band bending between layers will form a periodic well, alternately for electrons and holes. If the period of the structure is sufficiently small, typically less than 100 angstoms than the electron mean free path, a resonant state in both conduction and valence bands will occur. The resulting absorption edge of the composite layers is lower in energy. As a result, depending on the periodicity and doping profile, the shift can be adjusted. This aspect provides the adjustability of the long wavelength photo-detector.

Fig. 1 illustrates the energy band diagram of the periodically doped structure and its absorption edge Eg . Resonant stat...