Carbon Nanotube-Based Uncooled Bolometers: Advances and Progress

Discovery of infrared radiation (IR) was an important step in understanding the hidden secrets of nature, which could be unraveled only after “ seeing ” this invisible spectrum. This curiosity led to the development of “ artificial eyes ”, the so-called optoelectronic devices (OEDs). Among them, bolometers (BMs) were a special class of OEDs used to detect IR and, thus, collect the hidden information. The gradual progress of human civilization and scientific curiosity led to the discovery of various materials which were looked upon as the ultimate IR bolometric material. Carbon nanotube (CNT) was one of them, which, soon after its discovery, hinted toward its potential application toward IR BM. Its blackbody characteristics, high thermal conductivity, low thermal capacity, and high mechanical and chemical stability turned out to be the ideal characteristics for the BM. This Review aims to discuss the different class of bolometric materials and then elaborating CNT-based BMs exclusively. Various adopted methodologies, both from material as well as design perspectives are discussed intensively, and the technological progress is presented over the years.