A low energy charged particle detector having a diode with a first layer and a top layer physically coupled to the first layer. The intersection between the first layer and the top layer defines a junction. The top layer is composed of a two-dimensional material such as a chalcogen-based material, providing an electrically passivated exposed outer surface opposite to the junction. The outer surface is exposed to receive low-energy charged particles from external sources. An appropriate control circuit is coupled to the diode, and operable to recognize the incidence of a particle upon the outer surface as a change in current or voltage potential.