Optimizing light absorption in quantum dot infrared photodetectors by tuning surface confinement of surface plasmonic waves

Abstract

In this paper, we measured the transmission of the 2DSHA surface plasmonic structures and its variation with the hole diameters a of the 2DSHA structures. The relationship between the transmission and the hole diameters a is found to be different from the prediction of Bethe's diffraction theorem. We also found that the photocurrent of the quantum dot (QD) infrared photodetectors (QDIPs) with different QD active layer thicknesses show different dependence on the hole diameters a of the 2DSHA structures. The photocurrent of the QDIPs with 10 active QD layers (10-QDIPs) saturates and starts to decrease as the hole diameter a is larger than 1.6 µm, whereas that of the QDIPs with 20 active QD layers (20-QDIPs) increases linearly with the hole diameter. The difference in the hole-diameter dependence of the 10-QDIPs and the 20-QDIPs is attributed to the variation of the near-field spreading in the vertical (surface-normal) direction due to the change in the hole diameters. An over 6 time (6×) photocurrent enhancement is obtained by optimizing the hole diameter of the 2DSHA surface plasmonic structure.

Enhanced Optical Transmission through MacEtch‐Fabricated Buried Metal Gratings

“…A metal film capable of providing a near‐uniform lateral voltage/current distribution over the surface of a device, yet also capable of controlling, and enhancing, the coupling of incident radiation into the device, has potential for a broad range of light‐emitting and detecting optoelectronic devices. Such structures have been utilized for all‐optical modulation of light–matter interaction, active control of thin film transmission, and to improve light absorption in underlying photodetector structures . However, even without the losses from underlying active materials, passive EOT structures, from a purely light filtering standpoint, typically demonstrate un‐normalized peak transmission efficiencies well below 50%, never approaching the performance of traditional multilayer thin film filters, especially at optical frequencies.…”

Angular-dependent photodetection enhancement by a metallic circular disk optical antenna

“…After the MBE growth, the sample was processed into QDIPs with the MCDA optical antenna structure using the standard cleanroom fabrication process reported before. 8,19 Since the interaction of the SPRs with QDs depends on a few important parameters, such as the near-field E-field components, 8 the separation between the plasmonic structures and the QDs, 12 and the E-field polarization dependent selection rules in QDs, 13 the MCDA optical antenna, and the QDIP structures are carefully designed to achieve optimal interaction. The QDIP with the MCDA optical antenna shows higher photocurrent at all incident angles.…”

“…5 Through the plasmonic modes, optical antennas can change near-field E-field distributions. 19 Such plasmonic mode dependent near-field E-field distribution is critical for infrared sensing and imaging based on low-dimensional materials, such as quantum well infrared photodetectors (QWIPs) and quantum dot infrared photodetectors (QDIPs) 3,[10][11][12] due to the close interaction of near-field E-fields with the low dimensional light sensing materials and quantum selection rule defined photon-electron excitation. 8,13 SPR properties in circular patch optical nanoantennas have been analyzed using Bessel-type of SPR modes, 14 however, plasmonic mode excitation under linearly polarized plane wave incidence and its angular dependence have not been fully explored.…”

Surface Plasmonics and Its Applications in Infrared Sensing

“…The QDIP technology offers a promising technology in MWIR and LWIR photodetection due to the advantages provided by the three-dimensional (3D) quantum confinement of carriers-including intrinsic sensitivity to normal incident radiation [13], high photoconductive (PC) gain, high quantum efficiency [15] and photoresponsivity [16]. The normal incidence detection capability greatly simplifies the fabrication complexity for a large format (1K · 1K) FPA.…”

“…In addition, the SPR modes can also change EM field distribution and thus offers an effective technique for EM field engineering to achieve specific transmission and/or receiving patterns with polarization and detection spectrum engineering capability [11,16]. In this chapter, a brief review of the fundamental concepts of SPRs will be first given and followed by the description of their applications in infrared detections.…”