Top: illustration of proton-induced atomic ionization in the production of secondary electrons, through energy deposition ( E ) of an incident proton (of energy E 0 ). Bottom: calculated energy distribution of secondary electrons (δ-rays) in a CsPbBr 3 nanocrystal. The energy values of 2.36 eV and 5.36 eV correspond to the bandgap energy ( E g ) of the CsPbBr 3 nanocrystal and the minimal energy required to form an electron-hole pair, respectively.
