GaAs-based triangular barrier photodiodes with embedded type-II GaSb quantum dots

Abstract

We fabricate GaAs-based triangular barrier photodiodes (TBPs), in which type-II GaSb quantum dots (QDs) are embedded in the vertex part of their triangular barriers. Their current–voltage characteristics and photo-responses are studied at low temperatures to show that GaSb QDs enhance the number and lifetime of photo-generated holes that are trapped by QDs in the barrier, resulting in the increase in the electron current around positively charged QDs. An extremely high responsivity of 109 A/W is achieved.

InGaAs triangular barrier photodiodes for high-responsivity detection of near-infrared light

“…As a result, the barrier height of TBPs can be more precisely controlled by adjusting both the bias voltage and the accumulation of photogenerated holes; consequently, the responsivity of the TBP becomes typically about ten times larger than that of conventional phototransistors. [3][4][5][6][7] In recent works, we studied new types of TBPs in which quantum rods or dots are embedded in the barrier region of GaAs-based TBPs 8,9) and demonstrated that the detector performances can be greatly improved. In this work, we report on the fabrication and evaluation of InGaAs-based TBPs to show that they function as NIR=SWIR detectors with very high responsivity.…”