Simulation and Fabrication of Double Barrier Structure of P-I-N amorphous silicon (a-Si) device

Ida Hamidah, Kardiawarman, Budi Mulyanti, Andi Suhandi, Wilson W.Wenas

Data & Software Engineering Research Group
STEI-ITB, Jl. Ganeca No.10, Bandung 40132, Indonesia
 

The application of double barrier (DB) structure in p-i-n amorphous silicon (a-Si) device was studied. The theoretical study was done to obtain device parameters such as tunneling probability and current density. The tunneling probability was calculated by employing the Schroedinger equation, WKB approximation and Green function. Width of potential well, width and height of barrier were varied to obtain the highest tunneling probability value. The current density was contributed by diffusion, and tunneling current densities. It was found that current density had a peak of 3950 A/m² at 0.56 volt forward bias. Furthermore, the fabrication of p-i-n a-Si device with double barrier structure was successfully carried out. To realize the double barrier structure, optimization of optical band gap of barrier a-SiC:H was done by varying ratio of CH4 to [CH4+SiH4]. The fabrication of p-i-n a-Si device was then done by using Plasma Enhanced Chemical Vapor Deposition (PECVD) technique with a structure of glass substrate/TCO/p-a-Si:H (2.15 eV;140Å)/i-a-Si:H (1.81 eV;1800 Å)/barrier a-SiC:H (2.36 eV;45 Å)/potential well i-a-Si:H (1/81 eV; 30 Å)/barrier a-SiC:H (2.36 eV; 45 Å)/n-a-Si:H (1.81 eV;180 Å)/Al. The I-V characteristic of the device showed a peak current calue at 0.55 forward bias.

Download Article