Narrowband Monolithic Perovskite–Perovskite Tandem Photodetectors

Abstract

Narrowband photodetectors (PDs) are sought after for many applications requiring selective spectral response. The most common systems combine optical bandpass filters with broadband photodiodes. This work reports a method to obtain a narrowband response in a perovskite PD by the monolithic integration of a perovskite photoconductor and a perovskite photodiode. The spectral response of the tandem PD is determined by the bandgap energy difference of the two perovskites, and exhibits a full width at half maximum below 85 nm, an external quantum efficiency up to 68% and a high specific detectivity of ≈1012 Jones in reverse bias, enabling the device to detect weak light signals. The absorption profile of the narrowband PD can be tuned by changing the thickness and bandgap of the wide bandgap perovskite absorber.

De Novo Studies of Working Mechanisms for Self-Driven Narrowband Perovskite Photodetectors

“…22−25 Owing to the remarkable advantages in tunable band gap, high defect tolerance, long carrier diffusion length, strong light absorption ability, and high carrier mobility, 26−31 perovskite has emerged as a promising photoactive material for constructing high-performance narrowband photodetectors. 2,4,21 The continuous progresses of regulating the perovskite thickness and band gap as well as the distribution of trap state have given access to narrowband response with the desired response peaks and wavelengths. 4,18,21,25 By manipulating the generation, transport, recombination, and collection behaviors of carriers arising from the broad-band absorption spectrum, a narrowband external quantum efficiency (EQE) response could be obtained at specific wavelengths.…”

“…Photodetectors that convert light signals into electrical signals have attracted lasting attention in a wide range of fields such as image sensor, intelligent monitoring, biological detection, optical communications, and environmental surveillance. − Although both broad-band and narrowband photodetectors have found diverse applications, the narrowband photodetectors have received special attention now owing to the ever-increasing demand for color discrimination, biological sensing, artificial vision and industrial control, etc. − To achieve and promote the narrowband photoresponse, many interesting strategies have been proposed.…”

“…Photodetectors that convert light signals into electrical signals have attracted lasting attention in a wide range of fields such as image sensor, intelligent monitoring, biological detection, optical communications, and environmental surveillance. − Although both broad-band and narrowband photodetectors have found diverse applications, the narrowband photodetectors have received special attention now owing to the ever-increasing demand for color discrimination, biological sensing, artificial vision and industrial control, etc. − To achieve and promote the narrowband photoresponse, many interesting strategies have been proposed. The first scheme relies highly on the optical regulation to obtain the narrowband response by simply introducing a band-pass filter based on a broad-band photodetector, using an active material with a narrowband absorption property, , or constructing an optical cavity to excite absorption promotion at the particular wavelength. − The plasmon resonance effect can also be used to design narrowband photodetectors by regulating the resonant absorption peak intensity and wavelength .…”

Multimodal photodetectors with vacuum deposited perovskite bilayers

“…38 Recently, we have demonstrated a multilayer diode architecture which allowed for a narrowband response due to the integration of a perovskite photoconductor (acting also as an optical filter) and a perovskite photodiode. 39 This configuration is enabled by the use of vacuum deposition methods, which allow the fabrication of multilayer structures.…”

“…S4c and d, ESI †), three orders of magnitude lower compared to that of the narrowband photodiode with a similar device. 39 Nevertheless, the simple bilayer perovskite photodetector is capable of discriminating light with an intensity as low as 0.1 mW cm À2 in broadband mode, and 1 mW cm À2 in the narrowband mode. We also investigated the photodetector response speed to short laser pulses (Fig.…”