Current Density-Voltage and Capacitance-Voltage Characteristics of Pulsed Laser Deposited Nitrogen-Doped n-Carbon/p-Silicon Diode

The current density-voltage (J-V) and capacitance-voltage (C-V) characteristics of a p-n heterojunction device are studied. The device was fabricated by depositing nitrogen (N) doped carbon (C) thin film on/p-type silicon substrate by pulsed laser deposition (PLD) technique at room temperature. Camphor (C₁₀H₁₆O), a natural source, was used as the starting precursor for the carbon layer of the heterostructure. In order to dope the carbon thin films with different doping concentrations, gaseous N was incorporated in the PLD chamber with different partial pressure. Both the J-V and C-V characteristics reveal that the device behaves as a successful p-n junction device up to a certain nitrogen partial pressure (NPP) in the PLD chamber, and this is near about 30 mTorr. At higher NPP, the material properties of the grown carbon layer of the device change and the device performance deteriorates. The built-in potential of the device with varying NPP is also estimated and found them to agree well with the device characteristics.