Electrical and optical characterizations of (001)-oriented homoepitaxial diamond p-n junction

摘要

We have succeeded in fabricating (001)-oriented diamondp-n junctions with clear diode characteristics and conformed ultraviolet (UV) light emission by current-injection at room temperature. As p-n junctions, a phosphorus doped n-type layer was formed on (00l)-oriented boron doped j?-type one by applying an optimized homoepitaxial growth technique based on microwave plasma-enhanced chemical vapor deposition. Current-voltage characteristics showed a rectification ratio of 10~3 at + - 30 Vat room temperature. The existence of the space-charge layer at the vicinity of the p-n junction was confirmed from capacitance-voltage (C-V) characteristics. From C~(-2)-V characteristics at 773 K, the built-in potential was estimated as approximately 4.7 V. A strong UV light emission at 235 nm due to free exciton recombination with transverse-optical phonon was observed at forward current over 36 mA in these p-n junctions.