Photovoltaic characteristics of postdeposition iodine-doped amorphous carbon films by microwave surface wave plasma chemical vapor deposition

Abstract

The amorphous carbon thin films have been deposited on silicon and quartz substrates by microwave surface wave plasma chemical vapor deposition at low temperature (<100°C) in Ar∕CH4 phase gas. Doping of iodine has been done in the postdeposited films by exposing them in iodine vapor. The photovoltaic measurements of the films were carried out before and after iodine doping. The results show dramatic decrease of optical gap from 3.4 to 0.9 eV corresponding to nondoping to iodine doping conditions, respectively. The preliminary photovoltaic characteristics of the film deposited on n-type silicon substrate under light illumination (AM1.5, 100mW∕cm2) reveal a short-circuit current density of 1.15μA∕cm2, open-circuit voltage of 177 mV and fill factor of 21.7%.

Opto-electrical properties of amorphous carbon thin film deposited from natural precursor camphor

“…The important properties of any such carbon films are mapped by the methods used for deposition, sp 3 /sp 2 ratio, % of hydrogen, disorderliness in the films, etc. With the superior properties of carbon films (having high sp 3 percentage) such as micro-hardness like sapphire, low frictional coefficient, inertness to any aggressive chemical and also ability to coat geometrically complex bodies; these carbon films can be used in the applications like antisticking overcoats for computer disks [8], anticorrosive coating for surgical instruments [9], solar cells [10,11], electron field emission [12,13] and electrodes in electrochemical reactions [14], etc. It is worthwhile to mention that the nature and properties of carbon films play an important role in various applications.…”

Influence of substrate resistivity on photovoltaic characteristics of Pd‐doped amorphous carbon film/SiO2/Si heterojunction

“…Amorphous carbon (a‐C), a disordered structure of carbon forms, has stimulated a lot of research interest due to its variable network of sp 3 , sp 2 , and sp 1 hybrid bands 1. The a‐C materials, with their excellent mechanical, chemical, electrical, and optical properties, have been applied in many different fields, such as solar cells 2, 14–18, sensors 3–6, protective coating 7, and so on. In addition, due to the advantages of stability and low cost, the a‐C film shows great potential to substitute traditional Si and Mo materials for use in electronic devices 1.…”

“…First, the bandgap of a‐C film can be controlled in a relatively wide range of 0.2–3 eV by controlling the dose of doping or structures (e.g., sp 3 /sp 2 ratio, cluster size). Until now, a lot of work has been done to fabricate a‐C film/Si structure photovoltaic devices, in which the a‐C film was doped by B 14, P 16, I 2, Fe 17, N 18. Our group have successfully fabricated a a‐C:Pd film/SiO 2 /Si heterojunction solar cell, which shows an open‐circuit voltage ( V oc ) of 0.33 V, a short‐circuit current density ( J sc ) of 3.5 mA/cm 2 and a conversion efficiency ( η ) of 4.7% under light illumination of 15 mW/cm 2 15.…”

Photovoltaic and photoconductivity characteristics of (a‐C:Fe)/Al2O3/Si structure

“…The various forms of carbon have attracted a great deal of interest in recent years because of their unique structure and properties. Among various application of carbon material, recent study of solar cells [1][2][3] are quite interesting, such as amorphous carbon (a-C) [2][3][4], fullerences [5], and carbon nanotubes [6] as a versatile material in photovoltaic (PV) materials. Amorphous carbon is the earliest successful carbon-based semiconductor to replace silicon in the solar cell.…”