Colloidal Quantum Dot Photodetectors for Low-Noise High-Speed Depth Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photodetectors used in near-infrared (NIR) and short wave infrared (SWIR) spectral regions suffer from noise performance, cost structure, and manufacturability issues, lacking a scalable detector structure for high-speed detection.
Innovation Solution
An optical depth sensing system utilizing a colloidal quantum dot photodetector with colloidal quantum dots as light sensing elements, achieving rise times less than 5.0 ns and fall times less than 10.0 ns, combined with an active illumination source like a laser or LED.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photodetectors (Si-based, Ge-based, InGaAs, HgCdTe, InSb) are used in NIR and SWIR spectral regions, then detection capability is achieved, but noise performance deteriorates and cost structure worsens and manufacturability becomes difficult
Solution Approach 1:
The patent changes the material parameter from conventional semiconductors to colloidal quantum dots with specific size ranges (2-50 nm), which fundamentally alters the detection characteristics and enables low-noise operation in NIR and SWIR regions through quantum confinement effects
Solution Approach 2:
The patent employs composite material structures including core-shell quantum dot configurations (e.g., PbS core with CdS shell) to achieve both high detection capability and low noise performance by combining materials with complementary properties
2Reliability
If conventional photodetectors are used in NIR and SWIR spectral regions, then detection function is provided, but cost structure increases and manufacturability deteriorates
Solution Approach 1:
The patent replaces complex epitaxial growth and crystal fabrication processes with colloidal synthesis methods that use solution-phase chemistry, enabling low-cost, scalable manufacturing of quantum dot photodetectors with consistent performance
Solution Approach 2:
The patent changes the fabrication approach from high-precision solid-state processes to colloidal solution processing, allowing for simplified device assembly and scalable production while maintaining detection function
3Reliability
If conventional photodetectors are used, then detection is achieved, but response speed deteriorates (lack of high-speed detection capability)
Solution Approach 1:
The patent changes the temporal response characteristics by utilizing quantum dots with optimized size and composition that reduce carrier recombination times, achieving rise times <5.0 ns and fall times <10.0 ns through quantum confinement and surface passivation
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 system provides superior temporal response, low dark current, and cost-effective scalability, enabling high-speed depth sensing in industrial, consumer, and automotive applications.
Implementation Method 1
The colloidal quantum dot photodetector has colloidal quantum dots as a light sensing element
Data Source
AI summary
An optical depth sensing system is provided including an active illumination source; and a colloidal quantum dot photodetector. The colloidal quantum dot photodetector having colloidal quantum dots as a light sensing elements and the system has rise times that are less than 5.0 ns and fall times less than 10.0 ns.