Temperature‐Insensitive Efficient Inorganic Perovskite Photovoltaics by Bulk Heterojunctions

Abstract

Inorganic perovskite solar cells (IPSCs) emerge as an ideal candidate for applications beyond terrestrial implementation due to their robustness. However, underlying mechanisms regarding their photovoltaic process at different temperatures remain unclear. Based on a stable absorber of CsPbI2.85(BrCl)0.15, considerable variation of corresponding device performance is revealed over temperature and further demonstrates a simple approach to an effective reduction of such variation. Interestingly, this absorber is found to be excitonic with poor carrier transport even at an ambient temperature of 285 K and below. With a novel device configuration of a PTB7‐th/perovskite bulk heterojunction, exciton dissociation and carrier extraction is facilitated. The resultant solar cell attains a best power conversion efficiency (PCE) of 17.2% with the fill factor of ≈84%, which represents the highest‐efficiency γ‐phase IPSCs reported to date. Importantly, this device is less sensitive to operation temperature, wherein the PCE variation over the temperature range from 210 to 360 K is 60% suppressed compared with the reference. The approach is effectively extended to other IPSCs with different photoactive phases, which may shed light on realizing highly efficient IPSCs for specific scenarios such as polar regions, near‐space, and exoplanet exploration.

Universal Dynamic Liquid Interface for Healing Perovskite Solar Cells

“…As shown in Figure 5a and Table S4, Supporting Information, all the photovoltaic data of three devices including J SC , V OC , FF, and PCE decrease monotonically with respect to the elevated operation temperature, which is a common phenomenon in solar cells, even silicon, and GaAs solar cells. [68,69] The mechanism is the increased Urbach energy of perovskite film by increasing the temperature, which is dictated by the phonon density. These phonons interact substantially with free charges and thus limit the charge mobility.…”

Strategies for the preparation of high-performance inorganic mixed-halide perovskite solar cells

“…Several studies have demonstrated that the phase stability of CsPbX 3 perovskites can be effectively improved by combining different halogens. 81,82 To investigate the inuence of ternary mixed-halides on the lm crystallization mechanism and phase evolution of inorganic perovskite CsPbX 3 (X = I, Br, Cl) under spin-coating, Ma et al adopted the state-of-art in situ grazingincidence wide-angle X-ray scattering (GIWAXS) technique, as shown in Fig. 5e.…”

Organic Molecules in All‐Inorganic CsPbIxBr3−xPerovskite Solar Cells: Interface Modifiers or Precursor Additives

“…Thus, the higher charge extraction and lower charge recombination were achieved in DAP-treated allinorganic hole transport layer CsPbBr 3 PSCs. [83] The Poly [84,85] Meanwhile, an ultraviolet-visible light absorber of all-inorganic PSCs and a near-infrared light absorber of PBDTTT-E-T: IEICO were integrated to broaden photoresponse and their absorption spectrum. [86,87] Moreover, the photovoltaic parameters of CsPbI x Br 3Àx PSCs are summarized in Table 1, when the organic molecules were distributed at the interface.…”

“…[ 83 ] The Poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)] (PTB7‐th) was employed to form the bulk heterojunction (BHJ) and improve energy level alignment, further enhance the carrier extraction and performance of solar cells. [ 84,85 ] Meanwhile, an ultraviolet‐visible light absorber of all‐inorganic PSCs and a near‐infrared light absorber of PBDTTT‐E‐T: IEICO were integrated to broaden photoresponse and their absorption spectrum. [ 86,87 ] Moreover, the photovoltaic parameters of CsPbI x Br 3− x PSCs are summarized in Table 1 , when the organic molecules were distributed at the interface.…”