Article (Journal/Review)
Origin of photoresponse in black phosphorus phototransistors
Fecha
2014-08-29Registro en:
0959-6526 / 1879-1786
10.1103/PhysRevB.90.081408
000341027200002
Autor
Low, Tony
Engel, Michael
Steiner, Mathias
Avouris, Phaedon
Institución
Resumen
We study the origin of a photocurrent generated in doped multilayer black phosphorus (BP) phototransistors, and find that it is dominated by thermally driven thermoelectric and bolometric processes. The experimentally observed photocurrent polarities are consistent with photothermal processes. The photothermoelectric current can be generated up to a micrometer away from the contacts, indicating a long thermal decay length. With an applied source-drain bias, a photobolometric current is generated across the whole device, overwhelming the photothermoelectric contribution at a moderate bias. The photoresponsivity in the multilayer BP device is two orders of magnitude larger than that observed in graphene.