Wavelength-sensitive detector comprising photoconductor units each having different types of elongated nanostructures

• US 8,232,517 B2
• Filed: 10/06/2009
• Issued: 07/31/2012
• Est. Priority Date: 07/29/2005
• Status: Active Grant

• Current Assignee: Interuniversitair Micro-Electronica Centrum VZW (IMEC International)
• Original Assignee: IMEC International
• Inventors: Verhulst, Anne S., Vandervorst, Wilfried
• Primary Examiner(s): Legasse, Jr., Francis M
• Application Number:
  US12/574,531
• Publication Number:
  US 20100171025A1
• Time in Patent Office: 1,029 Days
• Field of Search: 250/214.1, 250/214.R, 257/448, 977/742, 977/932, 977/933, 977/954
• US Class Current: 250/214.1
• CPC Class Codes: H01L 31/0352 characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
• CPC Class Codes: H01L 31/09 Devices sensitive to infrared, visible or ultraviolet radiation H01L31/101 takes precedence
• CPC Class Codes: Y10S 977/954 Of radiant energy

Abstract

A wavelength-sensitive detector is provided that is based on elongate nanostructures, e.g. nanowires. The elongate nanostructures are parallel with respect to a common substrate and they are grouped in at least first and second units of a plurality of parallel elongate nanostructures. The elongate nanostructures are positioned in between a first and second electrode, the first and second electrodes lying respectively in a first and second plane substantially perpendicular to the plane of substrate, whereby all elongate nanostructures in a same photoconductor unit are contacted by the same two electrodes. Circuitry is added to read out electrical signals from the photoconductor units. The electronic density of states of the elongate nanostructures in each unit is different, because the material, of which the elongate nanostructures are made, is different or because the diameter of the elongate nanostructures is different. Each unit of elongate nanostructures therefore gives a different response to incident photons such that wavelength-specific information can be derived with the device.

Claims

1. A wavelength-sensitive detector comprising a first photoconductor unit and a second photoconductor unit on a substrate;

wherein a plane of the first photoconductor unit and a plane of the second photoconductor unit are substantially parallel to each other and are substantially perpendicular to a plane of the substrate;

wherein each photoconductor unit comprises a first electrode having a first longitudinal direction and a first sidewall lying in a first plane parallel with the first longitudinal direction and a second electrode having a second longitudinal direction and a second sidewall lying in a second plane parallel with said second longitudinal direction;

wherein the first photoconductor unit comprises a plurality of first type elongate nanostructures positioned in between the first electrode and the second electrode of the first photoconductor unit, the elongate nanostructures each having a longitudinal axis, wherein the longitudinal axes of the first type elongate nanostructures are substantially parallel to each other and are substantially perpendicular to a plane of the first electrode and a plane of the second electrode of the first photoconductor unit; and

wherein the second photoconductor unit comprises a plurality of second type elongate nanostructures positioned in between the first electrode and the second electrode of the second photoconductor unit, the elongate nanostructures each having a longitudinal axis, wherein the longitudinal axes of the second type elongate nanostructures are substantially parallel to each other and are substantially perpendicular to a plane of the first electrode and a plane of the second electrode of the second photoconductor unit, wherein the first type elongate nanostructures are different from the second type elongate nanostructures, wherein the detector is configured to determine a polarization of incident radiation, and wherein the first photoconductor unit comprises the first type elongated nanostructures oriented in a first direction and the second photoconductor unit comprises the second type elongated nanostructures oriented in a second direction, wherein the first direction and the second direction are substantially perpendicular to each other, and wherein the first photoconductor unit and the second photoconductor unit are stacked next to each other on the substrate.

2. A wavelength-sensitive detector comprising a first photoconductor unit and a second photoconductor unit on a substrate;

wherein a plane of the first photoconductor unit and a plane of the second photoconductor unit are substantially parallel to each other and are substantially perpendicular to a plane of the substrate;

wherein each photoconductor unit comprises a first electrode having a first longitudinal direction and a first sidewall lying in a first plane parallel with the first longitudinal direction and a second electrode having a second longitudinal direction and a second sidewall lying in a second plane parallel with said second longitudinal direction;

wherein the first photoconductor unit comprises a plurality of first type elongated nanostructures positioned in between the first electrode and the second electrode of the first photoconductor unit, the elongated nanostructures each having a longitudinal axis, wherein the longitudinal axes of the first type elongated nanostructures are substantially parallel to each other and are substantially perpendicular to a plane of the first electrode and a plane of the second electrode of the first photoconductor unit; and

wherein the second photoconductor unit comprises a plurality of second type elongated nanostructures positioned in between the first electrode and the second electrode of the second photoconductor unit, the elongated nanostructures each having a longitudinal axis, wherein the longitudinal axes of the second type elongated nanostructures are substantially parallel to each other and are substantially perpendicular to a plane of the first electrode and a plane of the second electrode of the second photoconductor unit, wherein the first type elongated nanostructures are different from the second type elongated nanostructures, wherein the first photoconductor unit comprises first type elongated nanostructures oriented in a first direction, wherein the second photoconductor unit comprises second type elongated nanostructures oriented in a second direction, wherein the first direction and the second direction are different, and wherein the first photoconductor unit and the second photoconductor unit are stacked next to each other on the substrate.