[Paper Review] Multiband Tunable Large Area Hot Carrier Plasmonic-Crystal Photodetectors

F. Pelayo Garcı́a de Arquer, Agustín Mihi+1 more|arXiv (Cornell University)|Jun 11, 2014

Plasmonic and Surface Plasmon Research26 references3 citations

TL;DR

This paper presents the first large-area, low-cost quasi-3D plasmonic crystal photodetector based on hot carrier collection at metal-semiconductor junctions, enabling multiband tunable response across the visible to near-infrared spectrum. It achieves unprecedented responsivity of 70 mA/W by engineering plasmonic nanostructures to tailor spectral sensitivity independently of the semiconductor bandgap.

ABSTRACT

Optoelectronic functionalities of photodection and light harnessing rely on the band-to-band excitation of semiconductors, thus the spectral response of the devices is dictated and limited by their bandgap. A novel approach, free from this restriction, is to harvest the energetic electrons generated by the relaxation of a plasmonic resonance in the vicinity of a metal-semiconductor junction. In this configuration, the optoelectronic and spectral response of the detectors can be designed ad hoc just by tailoring the topology of metal structures, which has tremendous applications in solar energy harvesting and photodetection. Fully exploiting hot electron based optoelectronics yet requires a platform that combines their exotic spectral capabilities with large scale manufacturing and high performance. Herein we report the first implementation of a large area, low cost quasi 3D plasmonic crystal (PC) for hot electron photodetection, showcasing multiband selectivity in the VIS-NIR and unprecedented responsivity of 70 mA/W.

Motivation & Objective

• To overcome the spectral limitations of conventional semiconductors by decoupling photodetection response from the material bandgap.
• To develop a scalable, low-cost platform for hot electron-based optoelectronics with tunable spectral response.
• To demonstrate high-performance photodetection using large-area plasmonic crystals that enable multiband selectivity.
• To achieve high responsivity in a manufacturable, quasi-3D plasmonic architecture.

Proposed method

• Design and fabrication of a large-area, quasi-3D plasmonic crystal structure using nanostructured metal arrays on a semiconductor substrate.
• Utilization of localized surface plasmon resonance (LSPR) in metal nanostructures to generate hot electrons upon light illumination.
• Engineering the geometry and periodicity of the plasmonic crystal to tune the resonant wavelength across the visible to near-infrared spectrum.
• Integration of a Schottky junction at the metal-semiconductor interface to extract hot electrons and generate photocurrent.
• Employing electron-beam lithography and metal deposition techniques for scalable fabrication of the plasmonic nanostructure array.
• Characterization of spectral response and responsivity under varied illumination conditions to validate multiband tunability and performance.

Experimental results

Research questions

• RQ1 Can a large-area plasmonic crystal structure enable multiband photodetection independent of the semiconductor bandgap?
• RQ2 What is the maximum responsivity achievable in a hot carrier photodetector using engineered plasmonic nanostructures?
• RQ3 Can plasmonic tuning be effectively achieved across the visible to near-infrared spectrum in a scalable, low-cost fabrication process?
• RQ4 How does the quasi-3D architecture enhance hot electron collection efficiency compared to planar designs?
• RQ5 What is the trade-off between spectral tunability, responsivity, and device scalability in hot carrier photodetectors?

Key findings

• The device achieves a responsivity of 70 mA/W, which is unprecedented for hot carrier photodetectors.
• Multiband spectral response across the visible to near-infrared range is demonstrated by tuning the plasmonic crystal geometry.
• The large-area, quasi-3D plasmonic structure enables efficient hot electron collection while maintaining tunability.
• The fabrication process is scalable and low-cost, suitable for industrial integration.
• The spectral response is decoupled from the semiconductor bandgap, enabling flexible design of optoelectronic response.
• The device operates effectively under broadband illumination due to the engineered plasmonic resonances.