Gity, F;Daly, A;Snyder, B;Peters, FH;Hayes, J;Colinge, C;Morrison, AP;Corbett, B

2013

July

Optics Express

Ge/Si heterojunction photodiodes fabricated by low temperature wafer bonding

Validated

Altmetric: 2 ()

CHEMICAL-VAPOR-DEPOSITION I-N GE HIGH-PERFORMANCE SI PHOTODETECTORS

21

17309

17314

We report on the photoresponse of an asymmetrically doped p(-)-Ge/n(+)-Si heterojunction photodiode fabricated by wafer bonding. Responsivities in excess of 1 A/W at 1.55 mu m are measured with a 5.4 mu m thick Ge layer under surface-normal illumination. Capacitance-voltage measurements show that the interfacial band structure is dependent on both temperature and light level, moving from depletion of holes at -50 degrees C to accumulation at 20 degrees C. Interface traps filled by photo-generated and thermally-generated carriers are shown to play a crucial role. Their filling alters the potential barrier height at the interface leading to increased flow of dark current and the above unity responsivity. (C) 2013 Optical Society of America

WASHINGTON

1094-4087

10.1364/OE.21.017309