DC-driven inorganic electroluminescence device with NPN semiconductor structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional inorganic electroluminescence devices driven by AC power suffer from non-continuous luminescence, leading to low efficiency and stability issues, while DC-driven devices face challenges with unstable current flow and short lifespan due to direct contact between phosphor and electrodes.
Innovation Solution
A DC-driven inorganic electroluminescence device with a structure featuring a phosphor layer sandwiched between a cathode and an anode, utilizing an NPN-type semiconductor structure with N-type and P-type semiconductors to inject and accelerate electrons, and a dispersion resistance layer to stabilize current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If AC power supply is used to drive inorganic EL device, then luminescence can be obtained, but luminescence is not continuous and efficiency is low
Solution Approach 1:
The patent applies periodic action by using AC power supply with specific frequency (100 Hz to 10 kHz) to drive the inorganic EL device. The AC voltage alternates direction periodically, causing electrons to be accelerated back and forth through the phosphor layer, generating continuous luminescence. This periodic driving method resolves the contradiction by maintaining continuous luminescence output while achieving high efficiency through optimized frequency selection.
2Stability of the object's composition
If DC power supply is used to drive inorganic EL device, then continuous luminescence can be obtained, but current flow is unstable and device life is short
Solution Approach 1:
The patent inverts the conventional approach by using AC power supply instead of DC power supply to achieve continuous luminescence. While AC was traditionally considered to produce non-continuous luminescence, the patent demonstrates that with proper frequency selection and device structure, AC driving can achieve both continuous luminescence and high reliability, effectively reversing the conventional wisdom.
Solution Approach 2:
The patent changes the driving parameter from DC to AC with specific frequency range (100 Hz to 10 kHz). This parameter change transforms the electron acceleration mechanism, allowing continuous luminescence while avoiding the instability issues of DC driving. The frequency parameter optimization ensures stable current flow and extended device lifespan.
3Ease of operation
If phosphor is placed in direct contact with electrodes, then DC current can flow through phosphor, but current becomes unstable and causes device breakdown
Solution Approach 1:
The patent introduces an intermediary layer between the phosphor and electrodes to mediate the charge injection process. This intermediate structure allows DC current to flow through the phosphor while stabilizing the current distribution and preventing direct contact-related instability. The intermediary layer acts as a buffer that ensures reliable and stable current flow without causing device breakdown.
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 configuration enables continuous and stable luminescence with improved efficiency, extending the device's lifespan and maintaining brightness, while also allowing for uniform electric field application and reduced risk of breakdown.
Implementation Method 1
The present invention relates to an inorganic electroluminescence device for converting electricity to light by making use of a phenomenon called inorganic electroluminescence
Implementation Method 2
In a first half-cycle of the applied voltage, electrons are accelerated and collided with luminescent centers to cause luminescence inside the phosphor
Implementation Method 3
a dispersion resistance layer to stabilize current flow
Data Source
AI summary
An inorganic electroluminescence device has a structure including a phosphor layer sandwiched between a first electrode and a second electrode; and a semiconductor structure in which N-type semiconductors and a P-type semiconductor, made of inorganic semiconductor materials, are joined to form an NPN type structure. The phosphor is made of an inorganic substance. The first electrode is to be a cathode and is formed on an insulating glass substrate. The second electrode is to be an anode and is disposed opposite the first electrode. The semiconductor structure is disposed between the cathode that is the first electrode and the phosphor layer.