Germanium/perovskite heterostructure for high-performance and broadband photodetector from visible to infrared telecommunication band

Abstract

A high-performance and broadband heterojunction photodetector has been successfully fabricated. The heterostructure device is based on a uniform and pinhole-free perovskite film constructed on top of a single-crystal germanium layer. The perovskite/germanium photodetector shows enhanced performance and a broad spectrum compared with the single-material-based device. The photon response properties are characterized in detail from the visible to near-infrared spectrum. At an optical fibre communication wavelength of 1550 nm, the heterojunction device exhibits the highest responsivity of 1.4 A/W. The performance is promoted because of an antireflection perovskite coating, the thickness of which is optimized to 150 nm at the telecommunication band. At a visible light wavelength of 680 nm, the device shows outstanding responsivity and detectivity of 228 A/W and 1.6 × 1010 Jones, respectively. These excellent properties arise from the photoconductive gain boost in the heterostructure device. The presented heterojunction photodetector provides a competitive approach for wide-spectrum photodetection from visible to optical communication areas. Based on the distinguished capacity of light detection and harvesting from the visible to near-infrared spectrum, the designed germanium/perovskite heterostructure configuration is believed to provide new building blocks for novel optoelectronic devices.

Copper Iron Sulfide Nanocrystal‐Bulk Silicon Heterojunctions for Broadband Photodetection

“…Besides these studies, the concept of extending the range of photodetection by making heterojunctions of two semiconductors with different bandgaps has been successfully utilized in the past. [ 40–43 ] A majority of these studies employ type‐I [42] or type ‐II [ 41 ] heterojunctions to separate carriers and further enhance carrier lifetimes and mobilities. This significantly improves the gain and responsivity of such devices.…”

“…Despite the short response times, we are able to observe high detectivities in the IR region. [ 42 ] Also, we emphasize the fact that our devices are capable of ultrabroadband detection with sensitivities extending from the visible to thermal wavelengths.…”

Strategies for Improving the Stability of Tin‐Based Perovskite (ASnX3) Solar Cells

“…The stability of the perovskite structure can be assessed using the Goldschmidt tolerance factor ( t ) (Equation ()) [ 35–37 ] …”

Crystallization Kinetics in 2D Perovskite Solar Cells

“…Perovskite has attracted significant interest owing to its high light absorption coefficients, long carrier lifetime and, diffusion length, as well as designable composition and characteristics, [1][2][3][4][5][6] for third-generation solar cells. [7][8][9][10][11][12] As a result of intensive research, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has rapidly risen from the original 3.8% to current 25.2% over the past ten years.…”