Fabrication of n+-poly-Si/p+-c-Si tunnel diode using Low-pressure Chemical Vapor Deposition for Photovoltaic Applications

In this paper, an n⁺-poly-silicon/p⁺-crystalline-silicon tunnel diode has been fabricated and characterized. The n⁺ poly-silicon layer is deposited by the low-pressure chemical vapor deposition method, while a diffusion furnace is used for boron diffusion in crystalline silicon. Scanning electron microscopy and X-ray diffraction pattern have been used for structural characterization. Hall measurement and current-voltage characteristics have been used for carrier density, mobility, current density, and contact resistance measurement. Hall measurement reveals the carrier density of ~10¹⁹ cm^-3 in phosphorus-doped poly-silicon tunnel layer with mobility of ~5.4 cm² V^-1-s^-1. The current-voltage characteristics of the tunnel diode show the current density of ~10³ Ampere/cm²