Recent advancements in optical thermometry based on photoluminescent perovskite oxides

Temperature is recognized as one of the most measured physical variables, given its necessity in practically all experimental and applied fields of science, engineering, medicine, and various aspects of daily human life. 1–4 Monitoring temperature holds paramount importance for several reasons. Firstly, temperature significantly impacts medical care for both humans and animals as well as the realms of food, beverage, and agriculture. Secondly, numerous types of equipment and machinery necessitate specific temperature ranges for optimal functionality. Exposure to excessive heat can lead to overheating of components, resulting in malfunctions or even complete failure, especially in electronic devices like computers and servers. High temperatures may also cause damage to individual components within the equipment. Furthermore, monitoring temperature enables the optimization of energy usage and cost reduction. For instance, in buildings, temperature sensors are employed to regulate heating and cooling systems, thereby reducing energy consumption and associated expenses. 1–3 , 5 According to marketsandmarkets, the temperature sensor market is anticipated to grow from 7.4 billion USD in 2024 to 9.7 billion USD in 2029, reflecting a compound annual growth rate (CAGR) of 5.6% during the forecast period. The projected growth is attributed to the increasing integration of temperature control systems in food safety management, Industry 4.0 and the Internet of Things (IoT), along with the expanding use of temperature in portable and healthcare equipment over the next five years. 6