Project Title:

High-Resolution, Low-power, Full-color TFEL Display Panels with

Spire Corporation
One Patriots Park
Bedford, MA 01730-2396


93-1- 09.19-6000

High-Resolution, Low-power, Full-color TFEL Display Panels with
Monolithically-Integrated Porous Polysilicon Light Emitters

Abstract:

Spire proposes to demonstrate visible electroluminescent (EL)
devices fabricated on porous polysilicon thin films on glass
substrates which can operate at an applied bias of only a few
volts. In Phase II, a working matrix of red, green, and blue
(RGB) EL devices for a full-color display panel will be
developed. Spire recently fabricated the first Si-based
light-emitting diodes configured as heterojunctions between an
electrochemically-processed p-type porous Si and an n-type
transparent semiconductor (indium-tin-oxide). Quantum confinement
in Si nanostructures is the key to the luminescence of these
devices. These LEDs emit yellow, orange, and red light: The
fabrication of a porous Si-based blue LED is presently being
investigated at Spire with government funding. Although most
previous work on porous silicon devices has employed bulk Si
materials rather than Si thin films, Spire has shown that bright
visible light can be obtained from porous structures formed on
polycrystalline silicon thin films deposited on quartz
substrates. Spire now proposes to extend this development to
create a novel thin film electroluminescent (TFEL) technology
based on porous polysilicon films. Such a technology would be not
only more economical and practical than conventional practice,
but could also offer the monolithic integration of display
elements with the thin film transistor (TFT) chip-on-glass driver
circuits.

This program offers a rare opportunity for a major advance in
flat-panel display technology. With all-silicon processing,
display panels can be fabricated in large volumes at a much lower
cost for applications such as high definition home televisions,
computer screens, and medical video imagers.

porous silicon, polysilicon, electroluminescence,
photoluminescence, displays, LED, TFEL, chip-on-glass