[paper] CV of Graphene–Silicon Heterojunction Photodiodes

Sarah Riazimehr,  Melkamu Belete,  Satender Kataria,  Olof Engström and Max Christian Lemme

Capacitance–Voltage (C –V) Characterization 

of Graphene–Silicon Heterojunction Photodiodes

Advanced Optical Materials 

First Published Open Access: 07 May 2020

DOI: 10.1002/adom.202000169

Abstract: Heterostructures of 2D and 3D materials form efficient devices for utilizing the properties of both classes of materials. Graphene/silicon (G/Si) Schottky diodes have been studied extensively with respect to their optoelectronic properties. Here, a method to analyze measured capacitance–voltage (C –V) data of G/Si Schottky diodes connected in parallel with G/silicon dioxide/Si (GIS) capacitors is introduced. The accurate extraction of the built‐in potential (Φbi) and the Schottky barrier height (SBH) from the measurement data independent of the Richardson constant is also demonstrated.

Figure 2

Fig.: a) Cross section of the test device showing both MIS and GIS regions. b) Small‐signal C –V characteristics of Dtest (line) compared to a theoretically calculated C –V curve (dashed ) at 10 kHz.

Acknowledgements: Financial support from the European Commission (Graphene Flagship, 785219, 881603) and the German Ministry of Education and Research, BMBF (GIMMIK, 03XP0210) is gratefully acknowledged.