A Lead‐free Organicnorganic Halide Perovskite Absorber with Photoconductive Response

Abstract

Perovskite hybrids of lead organometal halides, (e. g., CH 3 NH 3 PbX 3 , X=Cl, Br, I) have gained wide attention since their spectacular progress on optoelectronic technologies in recent years. However, it still remains the fundamental problem, namely, the existence of the toxic, bioaccumulative, polluting element Pb and the instability of humidity. In particular, the use of toxic Pb severely limits the broad applications and commercialization of lead-containing optoelectronic devices, and finding an alternative that preserves the unique optoelectronic properties of the lead halide perovskite is highly urgent. Bi 3 + exhibits isoelectronic behavior similar to that of Pb 2 + in terms of ion radius and electronegativity, which is expected as an environmentally friendly alternative for lead. However, 1D Bi-based hybrid organic-inorganic light-absorbing materials with pyridinium are not numerous. Although great progress has been made, the research on photoresponse behavior are still rarely reported. Here, we present a lead-free organic-inorganic hybrid absorber with photoconductive response, (C 5 H 7 N 2)BiI 4 (1, C 5 H 7 N 2 + is 2-aminopyridinium), which displays a narrow optical bandgap of~1.8 eV. Equally importantly, 1 not only features highly applicable properties, but is also able to absorb across most of the UV/Vis region of the solar spectrum. Furthermore, high-quality single crystal with sizes up to 7 × 6 × 4 mm 3 was successfully grown. In addition, 1 exhibited extremely low dark current (2 × 10 À 11 A) at the bias of 10 V, which indicates that the indicator of 1 is an order of magnitude lower than other reported perovskite photodetectors. Moreover, photocurrent on/off switches is faster (6 70 ms), indicating that 1 can be a promising photosensitive switch. These intriguing properties, namely the lead-free composition, a small band gap, and the fast photoconductive response, suggest promising applications in the field of optoelectronics.

Influence of interaction between organic cation and inorganic unit in bi-based hybrid perovskites for photoelectronic properties

“…To compare their crystal structures more clearly, the crystallographic packing diagrams of PDABI and PIDBI viewed along different unit cell directions are shown in Figure 1 , from which can be seen that their BiI 4 - anions all adopted the infinite one-dimensional (1D) chain that has been reported, such as (C 5 H 7 N 2 )BiI 4 [4ApyH]BiI 4 , (C 5 H 6 N)BiI 4 [ 26 , 27 , 28 ]. The 1D cation chains are vertical to [0, 1, 0] plane in PDABI ( Figure 1 a) and [−1, 0, 1] plane in PIDBI ( Figure 1 d), which all composed of edge-share BiI 6 octahedrons.…”

Evaporation crystallization of zero-dimensional guanidinium bismuth iodide perovskite single crystal for X-ray detection

“…Akin to the lead halide hybrid perovskites, large alkyl cations were then adopted to design bismuth halide perovskite for obtaining better humidity stability. [15][16][17][18] For instance, Nair et al designed and fabricated a (1,3-propanediammonium) 2 Bi 2 I 10 •2H 2 O film, and demonstrated a parallel configured photodetector with a responsivity of 1.14 mA W −1 and repeatable photocurrent in several light on/off cycles. 15 Besides, Zheng et al reported a novel (TMP) 1.5 [Bi 2 I 7 Cl 2 ] perovskite, and achieved obvious photoconductivity and high moisture and light stability.…”

Low power consumption photoelectric coupling perovskite memristor with adjustable threshold voltage

“…Because of the presence of movable ions in OHP, large electrical hysteresis loops will be formed in device operation, which is the precondition of achieving highly non-volatile memristors with high high resistance state (HRS)/low resistance state (LRS) ratio and repeatability [12]. In addition, perovskite is also an excellent photoelectric material, meaning that the memristors with OHP can open up new photoelectric coupling application fields for neural chips [13]. Based on the photoelectric conversion characteristics and synaptic plasticity of memristors with OHP, an integrated information collection and processing system for visual recognition can be realized.…”