Diamond-based vertical Schottky betavoltaic cell for extreme environment energy harvesting

The development of microelectromechanical systems operating in extreme environments necessitates critical advancements of power supply in meeting the calls for miniaturization, extended lifespan, enhanced reliability, and broad operating temperature tolerance. Exhibiting exceptional intrinsic properties, diamond is well positioned as promising candidates for such applications. In this work, an Au–metal/intrinsic/p-type (Au–MIP) diamond vertical Schottky betavoltaic cell using 63Ni source is fabricated successfully, which achieves an open-circuit voltage of 1.30 V, a short-circuit current density of 6.45 nA cm−2, giving a maximum output power density of 6.96 nW cm−2 and a device energy conversion efficiency of 2.41%, respectively. Moreover, a high fill factor of 0.83 is obtained for the betavoltaic cell. The 63Ni/Au-MIP cell performance are further evaluated under different working conditions including radiation source energies and operating temperatures, which exhibit great potentials to be used as nuclear batteries with good output characteristics. This work demonstrates its advantages of using diamond beta cells in the harsh conditions such as deep space, deep sea, and polar regions.