Nitride LED Injection Regions for Charge Carrier Transport
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Solution Overview
Problem
The internal quantum efficiency of nitride-based LEDs is reduced due to poor hole transport, often inhibited by the barrier height of quantum wells and the occurrence of polarization charges.
Innovation Solution
The semiconductor body includes injection regions within the semiconductor layer sequence, doped to match the first layer's conductivity type, allowing direct injection of charge carriers into the active layer, thereby enhancing charge carrier injection and quantum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional doping structure is used, then device structure is simple, but charge carrier injection into active layer is poor
Solution Approach 1:
The semiconductor layer is divided into multiple doping regions with different conductivity types. Injection regions with first conductivity type are created within the semiconductor layer to provide localized charge carrier injection paths, segmenting the uniform doping structure into functional zones that improve carrier transport to the active layer.
Solution Approach 2:
Different regions of the semiconductor layer are doped with different conductivity types to create localized functional zones. The injection regions have first conductivity type while other regions have second conductivity type, allowing each zone to perform its specific function optimally - injection regions for carrier injection and other regions for their respective functions.
2Reliability
If quantum well barrier height is high, then quantum well confinement is strong, but hole transport is inhibited
Solution Approach 1:
Injection regions are introduced as intermediary structures between the contact and the quantum wells. These regions provide a stepped injection path that mediates the transport of charge carriers across the quantum well barriers, reducing the energy loss at interfaces while maintaining strong carrier confinement within the quantum wells.
Solution Approach 2:
The charge carrier injection is extended from a single-interface process to a multi-step process occurring across multiple interfaces in the vertical dimension. Carrier injection occurs at multiple injection region interfaces rather than a single contact interface, distributing the energy loss across multiple smaller steps and improving overall transport efficiency.
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
This approach ensures uniform injection of charge carriers into quantum wells, increasing the overall efficiency of the semiconductor body by overcoming barriers to hole transport.
Implementation Method 1
within each injection region the semiconductor layer sequence is doped in such a way that the semiconductor layer sequence has the same conductivity type as the first layer within the entire injection region... at least some charge carriers pass from the first layer into the injection regions and are injected from there directly into the active layer
Data Source
AI summary
The invention relates to an optoelectronic semiconductor element (100) comprising a semiconductor layer sequence (1) with a first layer (10) of a first conductivity type, a second layer (12) of a second conductivity type, and an active layer (11) which is arranged between the first layer (10) and the second layer (12) and which absorbs or emits electromagnetic radiation when operated as intended. The semiconductor element (100) is equipped with a plurality of injection regions (2) which are arranged adjacently to one another in a lateral direction, wherein the semiconductor layer sequence (1) is doped within each injection region (2) such that the semiconductor layer sequence (1) has the same conductivity type as the first layer (10) within the entire injection region (2). Each injection region (2) passes at least partly through the active layer (11) starting from the first layer (10). Furthermore, each injection region (2) is laterally surrounded by a continuous path of the active layer (11), the active layer (11) being doped less in the path than in the injection region (2) or oppositely thereto. During the operation of the semiconductor element (100), charge carriers reach the injection regions (2) at least partly from the first layer (10) and are directly injected into the active layer (11) from there.