Zero-dimensional methylammonium iodo bismuthate solar cells and synergistic interactions with silicon nanocrystals

Abstract

Organometal trihalide perovskite solar cells have attracted monumental attention in recent years. Today's best devices, based on a three-dimensional perovskite structure of corner-sharing PbI octahedra, are unstable, toxic, and display hysteresis in current-voltage measurements. We present zero-dimensional organic-inorganic hybrid solar cells based on methylammonium iodo bismuthate (CHNH)(BiI) (MABI) comprising a BiI bioctahedra and observe very low hysteresis for scan rates in the broad range of 150 mV s to 1500 mV s without any interfacial layer engineering. We confirm good stability for devices produced and stored in open air without humidity control. The MABI structure can also accommodate silicon nanocrystals, leading to an enhancement in the short-circuit current. Through the material MABI, we demonstrate a promising alternative to the organometal trihalide perovskite class and present a model material for future composite third-generation photovoltaics.

Lead-free hybrid perovskites for photovoltaics

“…Typically, the MABI-based solar cells demonstrate a high resistivity to air oxidation and ambient humidity [85,155–157 160,168]. Similar high stability to the degradation under ambient atmosphere was reported for highly luminescent Cs 3 Bi 2 X 9 (X = Cl, Br, I) crystals emitting in a broad range from ≈390 to ≈550 nm depending on the composition of the halide component [164].…”

“…In the case of antimony, stable compounds of MA 3 Sb 2 I 9 [90,153], MASbSI 2 [87], and Cs 3 Sb 2 I 9 [88–90 154] were reported, while for bismuth, a larger array of compositions was studied, including MA 3 Bi 2 I 9 (MABI) [84–85 155–163], Cs 3 Bi 2 X 9 [164–165], and MA 2 KBiCl 6 [166]. The reported bandgaps of selected Bi- and Sb-based HPs are collected in Table 3.…”

“…MABI shows two distinct electron transitions near the absorption band edge – an indirect transition with E g i = 1.99 eV and a direct one with E g d = 2.15 eV [155]. Both transitions contribute to the light-harvesting by the Bi-based HPs as indicated by detailed PL studies on luminescent Cs 3 Bi 2 X 9 NCs [159].…”

Performance and stability gain in zero-dimensional perovskite solar cells after >2 years when hybridized with silicon nanocrystals

“…10 The high stability of MABI is further evidenced by the absence of hysteresis in MABI devices. 12 MABI was initially prepared as a lead-free alternative to OHPs but has not replicated the monumental rise in efficiency of lead-based OHPs. To date, the best cells have efficiencies of approximately 1.64%.…”

“…18 Furthermore, recently we showed the benets of incorporation of femtosecond laser surface-engineered silicon nanocrystals (SiNCs) to form perovskites/SiNCS based hybrids that can increase the efficiency of low-dimensional perovskite solar cells. 12 In this communication we report the results of the stability test of MABI solar cell devices with and without SiNCs aer a period of more than 2 years. Our investigation demonstrates highly stable MABI solar cells which show enhanced stability when incorporated with SiNCs, resulting in an increase in the performance aer >2 years.…”