High performance near infrared photodetector based on in-plane black phosphorus p-n homojunction

et al. 2021

Adv Funct Materials

Solution‐processed narrow‐bandgap Sn–Pb perovskites have shown their potential in near‐infrared (NIR) photodetection as a promising alternative to traditional silicon and inorganic compounds. To achieve efficient NIR photodetection, high‐quality Sn–Pb perovskite thick films with well‐packed, smooth, and pinhole/void‐free features are highly desirable for boosting the spectral absorption. Understanding the crystallization kinetics and tuning the crystallization are fundamentally important to reach such high‐quality thick Sn–Pb perovskite films, and have been limitedly explored. Herein, an approach of double‐side crystallization tuning through low‐temperature space‐restricted annealing in methylammonium‐free Sn–Pb perovskite films with over 1 µm thickness is proposed. More specifically, through simultaneously retarding the crystallization in the top of precursor films and promoting the crystal growth of the bottom of precursor films, high‐quality and block‐like thick FA0.85Cs0.15Sn0.5Pb0.5I3 perovskite films with improved crystallinity, preferred out‐of‐plane orientation, and reduced trap density are achieved. Finally, photovoltaic‐mode Sn–Pb perovskite NIR photodetectors show a high external quantum efficiency of ≈80% at 760–900 nm, a recorded responsivity of 0.53 A W−1, and a high specific detectivity of 6 × 1012 Jones at 940 nm. This study offers the fundamental understanding of the crystallization kinetics of thick perovskite films and paves the way for perovskite‐based emerging NIR photodetection and imaging applications.

Section: Resultsmentioning

confidence: 99%

Double‐Side Crystallization Tuning to Achieve over 1 µm Thick and Well‐Aligned Block‐Like Narrow‐Bandgap Perovskites for High‐Efficiency Near‐Infrared Photodetectors

Liu

Zhu

et al. 2021

Adv Funct Materials

“…Very recently, Xu et al. [ 41 ] presented a high‐performance BP‐based photodetectors. An in‐plane homojunction could be constructed by controlling external bias and gate voltage.…”

Section: Photodetectors Based On Single 2d Materialsmentioning

confidence: 99%

Recent Advances in 2D Materials for Photodetectors

Jiang

Wen

et al. 2021

Adv Elect Materials

116

Photodetection technology has been systematically studied due to wide practical applications in temperature monitoring, thermal image technology, and light communication systems. To date, photodetectors based on multitudes of 2D materials have been reported because of their excellent performance. On account of their novel physical properties with ultrathin thickness, cost‐effective preparation with mechanical transfer process, natural passivated surface without dangling bonds, various bandgaps corresponding with a wide photoresponse, and so on, new 2D materials emerge to play significant roles in the field of photodetection. In this regard, a great advance has been achieved in terms of preparation and device application, especially in the last decade. However, there are still some challenges to obtain high‐performance photodetectors, such as growing high‐quality 2D materials, achieving higher quantum efficiency, effectively separating the photogenerated electron–hole pairs, and so on. In this review, the recent development of the state‐of‐the‐art photodetection composed of 2D materials is summarized. Moreover, the key parameters and mechanisms in photodetectors are highlighted, and an overview on 2D materials and their heterostructures is provided. Finally, the strategies for improving the performance of photodetectors are also highlighted. The review will provide a guide to further practical applications in photodetection devices.

“…Because of the absorption of both BP and Bi 2 O 2 Se to infrared light, R reaches ∼ 9.5 A/W, ∼ 4.3 A/W and ∼ 2.3 A/W at 850 nm, 1330 nm and 1550 nm, respectively. This is at a superior level among the BP or Bi 2 O 2 Se based photovoltaic photodetectors, as summarized in Figure4(f)[27][28][29][30][31][32][33][34][35][36][37][38]. Whilst D* is calculated to be ∼ 5.3 × 10 9 Jones, ∼ 2.4 × 10 9 Jones and ∼ 1.…”

mentioning

confidence: 90%

Bi2O2Se/BP van der Waals heterojunction for high performance broadband photodetector

Xing

Yang

et al. 2021

Sci. China Inf. Sci.

Broadband photodetector has wide applications in the field of remote sensing, health monitoring and medical imaging. Two-dimensional (2D) materials with narrow bandgaps have shown enormous potential in broadband photodetection. However, the device performance is often restricted by the high dark currents. Herein, we demonstrate a high performance broadband photodetector by constructing Bi 2 O 2 Se/BP van der Waals heterojunction. The device exhibits a p-n diode behavior with a current rectification ratio of ∼20. Benifited from the low dark current of the heterojunction and the effective carrier separation, the device achieves the responsivity (R) of ∼ 500 A/W, ∼ 4.3 A/W and ∼ 2.3 A/W at 700 nm, 1310 nm and 1550 nm, respectively. The specific detectivity (D*) is up to ∼ 2.8 × 10 11 Jones (700 nm), ∼ 2.4 × 10 9 Jones (1310 nm) and ∼ 1.3 × 10 9 Jones (1550 nm). Moreover, the response time is ∼ 9 ms, which is more than 20 times faster than that of individual BP (∼ 190 ms) and Bi 2 O 2 Se (∼ 180 ms) devices.Keywords Bi 2 O 2 Se/BP, van der Waals heterojunction, broadband photodetector, low dark current, narrow bandgap