hBN Heterostructures for Deep UV and Neutron Detection
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Solution Overview
Problem
Current deep UV light sources and detectors are limited by cost, size, weight, power requirements, and performance, hindering their integration and effectiveness in various civilian and defense applications, particularly in neutron detection and ultraviolet spectral range operations.
Innovation Solution
Development of hexagonal boron nitride (hBN) semiconductor devices with heterostructures and epitaxially grown thin films for high-efficiency neutron detection and ultraviolet light emission, utilizing substrates like sapphire and GaN, and incorporating p-type dopants to enhance free hole injection and quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing semiconductor detector technology is used, then device integration and effectiveness are limited, but the devices can operate with current technology constraints
Solution Approach 1:
The patent combines neutron detection and ultraviolet emission functions into a single hBN semiconductor device platform. The heterostructure integrates multiple functional layers (hBN epilayers, buffer layers, contact layers) that simultaneously enable neutron capture, charge carrier generation, and UV light emission, eliminating the need for separate detection and emission devices.
Solution Approach 2:
The hBN-based semiconductor device serves multiple functions: it acts as a neutron detector with high capture efficiency, a deep UV light source, and a solid-state imaging detector. The material's unique properties (wide bandgap, high neutron capture cross-section, mechanical strength) enable this multi-functionality in a single device architecture.
2Productivity
If hBN semiconductor devices are developed for high efficiency, then neutron capture efficiency approaches 100%, but device fabrication complexity increases
Solution Approach 1:
The patent employs preliminary actions in the fabrication process by first growing high-quality hBN buffer layers and epilayers with controlled doping before device assembly. The epitaxial growth process pre-establishes the crystalline structure and electrical properties needed for high-efficiency neutron detection, simplifying subsequent device fabrication steps.
Solution Approach 2:
The device uses composite heterostructures combining hBN with other materials (e.g., GaN, AlN, SiC substrates, metal contacts). This composite approach leverages the strengths of each material: hBN for neutron capture and UV emission, III-nitride substrates for structural support and lattice matching, and metal layers for electrical contacts, achieving high performance while managing fabrication complexity.
3Reliability
If deep UV light sources are improved for better performance, then quantum efficiency increases, but device size and power requirements increase
Solution Approach 1:
The patent achieves high quantum efficiency by changing key material parameters: using hBN with its wide bandgap (∼6 eV) for deep UV emission, controlling doping concentrations to optimize charge carrier generation and transport, and adjusting layer thicknesses in the heterostructure. These parameter optimizations enable high efficiency in a compact device format without increasing weight.
4Measurement precision
If hBN epilayers are used for neutron detection, then detection resolution improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces mechanical fabrication methods with epitaxial growth techniques for creating hBN layers. The epitaxial process provides atomic-layer precision in thickness control and automatic self-alignment of crystal structures, achieving the manufacturing precision needed for high-resolution neutron detection without complex mechanical machining or lithography steps.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The hBN semiconductor devices achieve high efficiency in neutron detection and ultraviolet light emission, offering improved resolution, reduced size and weight, and low voltage operation, with potential for 100% neutron capture efficiency and enhanced quantum efficiency in deep UV emitters.
Implementation Method 1
one or more hexagonal boron nitride epilayers coated on the substrate... hBN based semiconductor neutron detectors have the potential to revolutionize neutron detection and dramatically enhance the capability for nuclear weapon detection
Implementation Method 2
The one or more hexagonal boron nitride epilayers may be individually doped with one or more p-type dopants selected from Si, Mg, C, Zn, Be
Implementation Method 3
light emitting devices... capable of emitting and detecting photons in the ultraviolet (UV) and extremely ultraviolet (EUV) spectral range
Data Source
AI summary
The present invention relates to optoelectronic device layer structures, light emitting devices, and detectors based upon heterostructures formed between hexagonal boron nitride (hNB) and III nitrides, and more particularly, to heterojunction devices capable of emitting and detecting photons in the ultraviolet (UV) and extremely ultraviolet (RUV) spectral range. The present invention also relates to neutron detectors based on epitaxially grown hBN thin films (or epitaxial layers) and hBN stacked thin films (or epitaxial layers) to satisfy the thickness required for capturing all incoming neutrons.