Formation of p-n⁺ diamond homojunctions by shallow doping of phosphorus through liquid emersion excimer laser irradiation

We report the fabrication of p-n ⁺ diamond homojunction through an innovative approach of laser irradiation in liquid-ambient. A shallow phosphorus-doped layer with a high electric conductivity is processed on top of a p-type diamond substrate to form the p-n ⁺ homojunction. The current–voltage measurements at room temperature confirmed high conductivity of the induced n⁺ layer and showed exceptional rectification properties with an ideality factor of 1.07, excellent low on-resistance of 3.7 × 10⁻² Ωcm², and current density over 260 Acm⁻² at forward-biasing of 10 V. Furthermore, undetectable leakage-current provides a rectification ratio exceeding 10¹⁰ at ±6 V, promoting the junction in UV detection applications.