Capacitance–Voltage Investigation of Encapsulated Graphene/Silicon Solar Cells
Ilaria Matacena, Pierluigi Guerriero, L. Lancellotti, E. Bobeico, Nicola Lisi, Rosa Chierchia, Paola Delli Veneri, Santolo Daliento
Abstract
In this article, the effect of graphene/silicon Schottky junction solar cells (G/Si SJSCs) encapsulation is investigated in terms of capacitance–voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> ) curves in the forward bias region. Capacitance behavior can give accurate information on interface properties, especially when it is considered at positive voltage. The detection of a double peak on such curve is related to nonuniform interface properties at the graphene/silicon interface. To passivate the interface, G/Si SJSCs have been exposed to HNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> vapors and the effectiveness of HNO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> doping has been exploited as well as its volatility, assessing the need for encapsulation. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> curves collected over time from doped unencapsulated G/Si SJSCs clearly exhibited a modification of capacitance behavior, revealing a fading of doping beneficial effects over a week. On the contrary, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${C}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> curves acquired from encapsulated samples evidence that capacitance behavior did not modify over time.