Photoluminescence | Wikipedia audio article
Channel: wikipedia tts
Date: 02/10/2019

This is an audio version of the Wikipedia Article:
https://en.wikipedia.org/wiki/Photoluminescence


00:01:19 1 Forms
00:04:39 2 Photoluminescence properties of direct-gap semiconductors
00:06:08 2.1 Ideal quantum-well structures
00:07:01 2.1.1 Photoexcitation
00:09:08 2.1.2 Relaxation
00:12:37 2.1.3 Radiative recombination
00:14:33 2.2 Effects of disorder
00:16:35 3 Photoluminescent material for temperature detection
00:16:55 4 Experimental Methods
00:17:50 5 See also



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

Listen on Google Assistant through Extra Audio:
https://assistant.google.com/services/invoke/uid/0000001a130b3f91
Other Wikipedia audio articles at:
https://www.youtube.com/results?search_query=wikipedia+tts
Upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts
Speaking Rate: 0.8555612629488678
Voice name: en-AU-Wavenet-C


"I cannot teach anybody anything, I can only make them think."
- Socrates


SUMMARY
=======
Photoluminescence (abbreviated as PL) is light emission from any form of matter after the absorption of photons (electromagnetic radiation). It is one of many forms of luminescence (light emission) and is initiated by photoexcitation (i.e. photons that excite electrons to a higher energy level in an atom), hence the prefix photo-. Following excitation various relaxation processes typically occur in which other photons are re-radiated. Time periods between absorption and emission may vary: ranging from short femtosecond-regime for emission involving free-carrier plasma in inorganic semiconductors up to milliseconds for Phosphorescence processes in molecular systems; and under special circumstances delay of emission may even span to minutes or hours.
Observation of photoluminescence at a certain energy can be viewed as an indication that an electron populated an excited state associated with this transition energy.
While this is generally true in atoms and similar systems, correlations and other more complex phenomena also act as sources for photoluminescence in many-body systems such as semiconductors. A theoretical approach to handle this is given by the semiconductor luminescence equations.