Large tunable photoeffect on ion conduction in halide perovskites and implications for photodecomposition

Kim, Gee Yeong; Senocrate, Alessandro; Yang, Tae‐Youl; Gregori, Giuliano; Grätzel, Michaël; Maier, Joachim

doi:10.1038/s41563-018-0038-0

Cited by 439 publications

(590 citation statements)

References 40 publications

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“…[10] The photo-excited neutral iodine with high activity might tend to diffuse into PTAA in which iodine activity is much lower. The existence of iodine in PTAA stems from the diffusion of iodine from the perovskite to the PTAA layer by O 2 and light.…”

Section: Perovskite Solar Cellsmentioning

confidence: 99%

Achieving Long‐Term Operational Stability of Perovskite Solar Cells with a Stabilized Efficiency Exceeding 20% after 1000 h

et al. 2019

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Perovskite solar cells (PSCs) with mesoporous TiO 2 (mp‐TiO 2 ) as the electron transport material attain power conversion efficiencies (PCEs) above 22%; however, their poor long‐term stability is a critical issue that must be resolved for commercialization. Herein, it is demonstrated that the long‐term operational stability of mp‐TiO 2 based PSCs with PCE over 20% is achieved by isolating devices from oxygen and humidity. This achievement attributes to systematic understanding of the critical role of oxygen in the degradation of PSCs. PSCs exhibit fast degradation under controlled oxygen atmosphere and illumination, which is accompanied by iodine migration into the hole transport material (HTM). A diffusion barrier at the HTM/perovskite interface or encapsulation on top of the devices improves the stability against oxygen under light soaking. Notably, a mp‐TiO 2 based PSC with a solid encapsulation retains 20% efficiency after 1000 h of 1 sun (AM1.5G including UV) illumination in ambient air.

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Section: Perovskite Solar Cellsmentioning

confidence: 99%

Achieving Long‐Term Operational Stability of Perovskite Solar Cells with a Stabilized Efficiency Exceeding 20% after 1000 h

et al. 2019

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“…We recall that I· diffusion has been documented and is supposed to occur mainly through site exchange between interstitial iodine (I i X ) and lattice iodide (I I X ) with hole exchange, [19,58] so involving the lead halide sublattice. Here we refer to "I PSK " to account for the articulate valence chemistry of iodine and polyiodide (or polyhalide) compounds (I 2 − , I 3 − , and the mixed halide respective).…”

Section: Resultsmentioning

confidence: 99%

“…[12] Moreover, ionic diffusion from electrodes is enhanced at high temperatures and causes irreversible degradation. [19] Interestingly, together with the decomposition paths it brings about, the iodide photoelectrochemistry has been recently invoked as a possible reason for the high defect tolerance of perovskites. [16,17] Furthermore, UV light accelerates perovskite degradation, for instance, by promoting the reaction of perovskites with TiO2, [18] and photo-oxidation of iodide to interstitial iodine.…”

Section: Introductionmentioning

confidence: 99%

Stability and Dark Hysteresis Correlate in NiO‐Based Perovskite Solar Cells

Girolamo

Matteocci

Kosasih

et al. 2019

Advanced Energy Materials

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for commercialization. [2,3] Thus, if metal halide perovskite (PSK) solar cells are to take part in supplying the world's energy demand, device stability must be significantly improved.Several kinds of stimuli have been found to degrade PSCs. When exposed to moist atmosphere, CH 3 NH 3 PbI 3 (MAPI) undergoes an irreversible degradation via the formation of hydrated phases. [4,5] Even the all-inorganic perovskite CsPbBr 3 undergoes intricate structural modifications when exposed to relative humidity (RH) above 60%, highlighting the sensitivity of lead halide perovskites to moisture also in the absence of organic cations. [6] Perovskites are also sensitive to atmospheric oxygen, which can rapidly diffuse inside the perovskite film through grain boundaries and inside the lattice via iodine vacancies. [7] Under illumination, the superoxide anion (O 2 − ) forms, which is highly reactive and triggers lattice decomposition. [8,9] Nevertheless, proper encapsulation procedures [10,11] can mitigate or, in the best scenario, eliminate the influence of moisture or oxygen on device stability. In addition to that, metal halide perovskites are also sensitive to heat, illumination, and electrical bias, three certain conditions in photovoltaic operation. In perovskite solar cells (PSCs), the interfaces are a weak link with respect to degradation. Electrochemical reactivity of the perovskite's halides has been reported for both molecular and polymeric hole selective layers (HSLs), and here it is shown that also NiO brings about this decomposition mechanism.Employing NiO as an HSL in p-i-n PSCs with power conversion efficiency (PCE) of 16.8%, noncapacitive hysteresis is found in the dark, which is attributable to the bias-induced degradation of perovskite/NiO interface. The possibility of electrochemically decoupling NiO from the perovskite via the introduction of a buffer layer is explored. Employing a hybrid magnesiumorganic interlayer, the noncapacitive hysteresis is entirely suppressed and the device's electrical stability is improved. At the same time, the PCE is improved up to 18% thanks to reduced interfacial charge recombination, which enables more efficient hole collection resulting in higher V oc and FF.

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“…Changing the halogen species from chlorine to iodine drastically shifts the light emitted from the resulting LHPs from near‐ultraviolet to near‐infrared (Figure d) . Exploiting alloyed halide species at various ratios to occupy site‐X allows the flexible tuning of the bandgap of the resulting LHPs, resulting in continuously adjustable emissive spectra across the entire visible range (Figure d) . By comparison, the A‐cation plays a minor role in determining the energy level configuration of LHPs.…”

Section: Fundamental Properties Of Lhp‐ncsmentioning

confidence: 99%

Section: Fundamental Properties Of Lhp‐ncsmentioning

confidence: 99%

Light Generation in Lead Halide Perovskite Nanocrystals: LEDs, Color Converters, Lasers, and Other Applications

Yan

Tan

et al. 2019

Small

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Facile solution processing lead halide perovskite nanocrystals (LHP‐NCs) exhibit superior properties in light generation, including a wide color gamut, a high flexibility for tuning emissive wavelengths, a great defect tolerance and resulting high quantum yield; and intriguing electric feature of ambipolar transport with moderate and comparable mobility. As a result, LHP‐NCs have accomplished great achievements in various light generation applications, including color converters for lighting and display, light‐emitting diodes, low threshold lasing, X‐ray scintillators, and single photon emitters. Herein, the considerable progress that has been made thus far is reviewed along with the current challenges and future prospects in the light generation applications of LHP‐NCs.

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Large tunable photoeffect on ion conduction in halide perovskites and implications for photodecomposition

Cited by 439 publications

References 40 publications

Achieving Long‐Term Operational Stability of Perovskite Solar Cells with a Stabilized Efficiency Exceeding 20% after 1000 h

Achieving Long‐Term Operational Stability of Perovskite Solar Cells with a Stabilized Efficiency Exceeding 20% after 1000 h

Stability and Dark Hysteresis Correlate in NiO‐Based Perovskite Solar Cells

Light Generation in Lead Halide Perovskite Nanocrystals: LEDs, Color Converters, Lasers, and Other Applications

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