Triangular-barrier quantum rod photodiodes: Their fabrication and detector characteristics

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

“…To improve the performance of TB photodiodes (TBPs), we have recently fabricated a TBP, where InGaAs quantum rods (QRs) are embedded within the TB to force electrons to flow through QRs. 5) The responsivity of such QR-TBPs reaches 10 5 A=W because photoholes are trapped by rods and lower the barrier, thus enhancing the current through QRs. In this work, we explore another way to improve the performances of TBPs by employing a structure, where a sheet of type-II GaSb quantum dots (QDs) is inserted in the vertex of a GaAs TB, so that photoholes are trapped by QDs and lower the local barrier height around charged dots.…”

“…This separation of electrons and holes reduces the recombination rate and prolongs the lifetime of holes. 12) First, the current-voltage (I-V ) characteristics of the type-A diode were measured at a temperature of 77 K, as shown by curves from (1) to (5) in Fig. 3.…”

“…This value is almost 10 6 times higher than that of a conventional TBP [1][2][3][4] and 10 4 times higher than that of a quantum rod TBP. 5) Here, the responsivity is defined in the region of the saturation current, which is reached after long illumination.…”

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.…”