Semiconductor nanoparticles, method for producing semiconductor nanoparticles, and light-emitting body

The semiconductor nanoparticles are formed from an Ag-Ge-S compound semiconductor. Furthermore, the content ratio of the Ag component and the Ge component is 1.0 or more and less than 7.5, preferably 1.8 or more and less than 7.3 in terms of molar ratio, the average particle diameter is 9 nm or less, and the difference between the maximum value and the minimum value of the particle diameter is suppressed to 3 nm or less. The semiconductor nano particles emit light in a near infrared region of 700 to 1000 nm. The semiconductor nanoparticles are synthesized at a reaction temperature of 150 DEG C or more and less than 250 DEG C, preferably 220 DEG C or less. The compound semiconductor may be used as a core particle, and a coating layer may be formed on the surface of the core particle. The light-emitting body contains the semiconductor nanoparticles. As a result, semiconductor nanoparticles which are safe and easy to handle and which can emit light in the near-infrared region, a method for producing the semicond