pho·​to·​tran·​sis·​tor ˌfō-tō-tran-ˈzi-stər How to pronounce phototransistor (audio)
: a photoconductive semiconductor device used especially as a photodetector

Example Sentences

Recent Examples on the Web The capsule has tiny phototransistors that send the light information to a microprocessor, which broadcasts it wirelessly to a computer or smartphone. Sean Rossman, USA TODAY, 25 May 2018 Not much, but enough for a custom phototransistor to capture it and relay that information to a microprocessor—which sent the signal to an Android app developed by an undergraduate engineering student. Megan Molteni, WIRED, 24 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'phototransistor.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

First Known Use

1950, in the meaning defined above

Time Traveler
The first known use of phototransistor was in 1950

Dictionary Entries Near phototransistor

Cite this Entry

“Phototransistor.” Dictionary, Merriam-Webster, Accessed 27 Nov. 2022.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Commonly Confused Words Quiz

  • vector image of a face with thought expression
  • I went to the ______ store to buy a birthday card.
Spell It

Hear a word and type it out. How many can you get right?

Universal Daily Crossword

A daily challenge for crossword fanatics.