Diamond photovoltaic radiation sensor using pn junction

Abstract

Because of its heat resistance and radiation hardness, diamond is a suitable semiconductor material for use in radiation sensors operating under harsh environments. To date, diamond radiation sensor designs have been constrained to Metal–Insulator–Metal structures. Instead of this structure, the pn junction offers several advantages for radiation sensors such as high built-in bias, electric field control, and depletion layer thickness control through doping profile design. We formed diamond pn diodes with ideal electric properties. A large built-in bias of 4.7 eV was obtained. The diode represented less than 10−11 A of low leakage current up to nearly 1 MV/cm of a high electric field. We detected alpha particles at zero-bias voltage using the pn diode, which opens the possibility of realizing compact radiation sensors.