Optoelectronics
- (Bern, Switzerland - Alvin Wei-Cheng Wong)
- Optoelectronics
Opto-electronics (or optronics) is the study and application of electronic devices and systems that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation. Important applications of optoelectronics include: Optocoupler, Optical fiber communications
Optoelectronics is based on the quantum mechanical effects of light on electronic materials, especially semiconductors, sometimes in the presence of electric fields.
- Photoelectric or photovoltaic effect, used in: photodiodes (including solar cells), phototransistors, photomultipliers optoisolators, integrated optical circuit (IOC) elements
- Photoconductivity, used in: photoresistors, photoconductive camera tubes, charge-coupled imaging devices
- Stimulated emission, used in: injection laser diodes, quantum cascade lasers
- Lossev effect, or radiative recombination, used in: light-emitting diodes or LED, OLEDs
- Photoemissivity, used in: photoemissive camera tube
- Perovskite quantum dots (PQDs)
Perovskite quantum dots (PQDs) are semiconducting nanocrystals with diameters of 2-10 nanometers. They have unique properties that make them useful in many optoelectronics areas, such as:
- Light-emitting diodes
- Lasers
- Photodetectors
- Solar cells
PQDs have several properties, including:
- High defect tolerance
- Quantum size effects
- Near perfect photoluminescent quantum yield
- Organic-inorganic hybrid structure
PQDs can be classed as:
Organic-inorganic hybrid, where A is an organic cation such as methylammonium (MA) or formamidinium (FA), or fully inorganic (A=Cs)
Mixed halide perovskites, where X is a mixture of Cl/Br or Br/I
For visible optoelectronic applications, the nanocrystals are generally synthesized to have a size of 4 – 15 nm.
Scientists at Australia's University of Queensland set a new world efficiency record for a quantum dot solar cell. The group fabricated a 0.1cm² device from a perovskite material and measured power conversion efficiency at 16.6%.
[More to come ...]
