Effect of sulfur-doped graphene quantum dots incorporation on morphological, optical and electron transport properties of CH3NH3PbBr3 perovskite thin films

Kadian, Sachin; Tailor, Naveen Kumar; Chaulagain, Narendra; Shankar, Karthik; Satapathi, Soumitra; Manik, Gaurav

doi:10.1007/s10854-021-06272-z

Cited by 21 publications

(13 citation statements)

References 51 publications

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“…Despite having notable efficiency and exceptional optoelectronic characteristics, lead-halide perovskites are still a long way from the commercialization or real-world acceptance because of important concerns such as the toxicity of lead (Pb) and the poor stability of lead-based perovskites in the presence of heat, oxygen, moisture, electric field, and light. − As an alternative to lead, bismuth-based perovskites have emerged, where both of the above-said problems of lead perovskites can be addressed simultaneously. − Consequently, metal-halide lead-free halide double perovskites with A 2 B(I)B(III)X 6 composition are recently surging as promising alternatives for Pb-based halide-perovskites. − Of these double perovskites, Cs 2 AgBiBr 6 has gained considerable attention in both photovoltaics and detection applications, with high stability and low toxicity. − Indeed, to date, Cs 2 AgBiBr 6 -based solar cells exhibited a power conversion efficiency of more than 4%, and Cs 2 AgBiBr 6 single crystals-based X-ray detectors demonstrate high sensitivity and low detection of the limit of 59.7 nGy/s …”

Section: Introductionmentioning

confidence: 99%

Dielectric Relaxation and Polaron Hopping in Cs₂AgBiBr₆ Halide Double Perovskites

et al. 2022

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The lead-free Cs2AgBiBr6 double perovskites have recently emerged as promising candidates for optoelectronic applications due to their less toxicity and high stability. Although the photophysical study of Cs2AgBiBr6 has been extensively explored, the same for dielectric relaxation and carrier conduction remains elusive. Here, we uncover the dielectric relaxation and charge conduction mechanism in the Cs2AgBiBr6 single crystals using temperature-dependent electrochemical impedance spectroscopy in correlation with modulus spectroscopy. We found that the ionic displacement and space charge polarization are mainly responsible for the dielectric response. A sharp transition frequency as ∼191 Hz for 0 °C to ∼492 Hz for 90 °C was observed in the dielectric constant (ε′) versus temperature study, where dε′/dT exhibits a positive and negative coefficient below and above the transition frequency, respectively. Stevels model analysis suggests that the contribution of traps reduces with the increase in temperature and therefore conduction enhances. This model also confirms the polarons as the main conduction carriers in the Cs2AgBiBr6 semiconductor. The polaron hopping and binding energy were estimated as W H = 0.17 eV and E P = 0.34 eV, respectively. The binding energy of the polaron is larger than the room-temperature thermal energy, indicating the polaron hopping instead of free charge carrier transport as the dominant conduction mechanism. Furthermore, the imaginary part of -Z″ and M″ demonstrates the temperature-activated polaron relaxation from non-Debye type to Debye type process in Cs2AgBiBr6 crystals. Our study provides fundamental insights into the dielectric relaxation behavior needed for developing efficient dielectric switches and unveils the details of the carrier conduction mechanism in lead-free double perovskites.

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Section: Introductionmentioning

confidence: 99%

Dielectric Relaxation and Polaron Hopping in Cs₂AgBiBr₆ Halide Double Perovskites

et al. 2022

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“…A series of peaks was obtained for the modified CFs in the regions 3340, 3270-3290, 2850-2950, 1640-1630, 1550-1510, 1490-1440, 1380-1300, 1295-1220, 1195-1100.5, 1007, 780-750, and 695-680 cm À1 . For enzymetreated (LO x /GO x ) CFs, peaks indexed at 3340.95-3337.78, 2950-2850, 1636-1637.8, 1510-1549, 1450-1370, 1340-1240 cm À1 correspond to -O-H group stretching from proteins, [31,32,[39][40][41][42] -C-H stretching of CH/CH 2 groups from the graphitic backbone of CFs, >C═O groups in the enzyme, -C-N amide bands (II), -C-H bending structures, and -C-N amide bands (III), respectively. Similarly, AOCE-6-modified CF shows peaks at 1220-1180, 2900-2860, 1500-1590 cm À1 , which are attributed to -C-O-C stretching of the crown ether, -C-H stretching of CH/CH 2 groups from the graphitic backbone of CFs, and -C═C stretching, respectively.…”

Section: Preparation and Characterization Of Cf Wes And Electrolytementioning

confidence: 99%

Microneedle‐Integrated Device for Transdermal Sampling and Analyses of Targeted Biomarkers

et al. 2023

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Currently available point‐of‐care systems for body fluid collection exhibit poor integration with sensors. Herein, the design of a disposable device for interstitial fluid (ISF) extraction as well as glucose, lactate, and potassium ion (K+) monitoring is reported on. It is minimally invasive and appropriate for single use, minimizing the risk of infection to the user. This microscale device contains a 3D‐printed cap‐like structure with a four‐by‐four microneedle (MN) array, bioreceptor‐modified carbon fiber (CF)‐sensing surface, and negative pressure convection technology. These features are incorporated within a compact, self‐contained, and manually operated microscale device, which is capable of withdrawing ≈3.0 μL of ISF from the skin. MN arrays applied with an upward driving force may increase the ISF flow rate. Moreover, functionalized CF working electrodes (WE1, WE2, WE3) are shown to selectively detect lactate, glucose, and K+ with high sensitivities of 0.258, 0.549, and 0.657 μA μm−1 cm−2 and low detection limits of 0.01, 0.080, 0.05 μm, respectively. Ex vivo testing on porcine skin is used to detect the ISF levels of the biomarkers. The microscale device can be a replacement for current point‐of‐care diagnostic approaches.

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“…prepared perovskite films doped with S‐GQDs, and the incorporation of S‐GQDs improved the light absorption of CH 3 NH 3 PbBr 3 films. [ 17 ] In our previous research, GQDs/Zn 0.9 Cd 0.1 Se composite exhibited better photoelectric properties than Zn 0.9 Cd 0.1 Se. The doping of GQDs improved the carrier density and lifetime, and effectively improved the photoelectric properties of Zn 0.9 Cd 0.1 Se.…”

Section: Introductionmentioning

confidence: 99%

Doped Graphene Quantum Dots Modified Zn_0.9Cd_0.1Se for Improved Photoelectric Properties

Lei

Chen

et al. 2023

Part & Part Syst Charact

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S‐graphene quantum dots (GQDs), N‐GQDs, P‐GQDs, and Cl‐GQDs are prepared by a solution chemistry method and further incorporated with ZnxCd1−xSe by one‐step hydrothermal method. In the previous study, ZnxCd1−xSe reached the optimal photoelectric performances at the Zn/Cd ratio of 0.9:0.1, so the Zn0.9Cd0.1Se were combined with doped GQDs (D‐GQDs) to form Zn0.9Cd0.1Se/doped‐GQDs. The influence of GQDs doped with different elements on the photoelectric properties of Zn0.9Cd0.1Se composites is discussed. Compared with pristine Zn0.9Cd0.1Se, Zn0.9Cd0.1Se/Cl‐GQDs, and Zn0.9Cd0.1Se/P‐GQDs can improve the photocurrent response and current intensity, therein, Zn0.9Cd0.1Se/Cl‐GQDs reaches the lowest interfacial charge transfer resistance and the highest photocurrent response of 5.48 × 10−6 A cm−2. Mott–Schottky analysis shows that the fitting slope of Zn0.9Cd0.1Se/Cl‐GQDs composites is significantly lower than that of Zn0.9Cd0.1Se/GQDs with other doped elements. The results indicate that Zn0.9Cd0.1Se/Cl‐GQDs composites has the largest carrier density, which is beneficial to charge conduction.

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Effect of sulfur-doped graphene quantum dots incorporation on morphological, optical and electron transport properties of CH3NH3PbBr3 perovskite thin films

Cited by 21 publications

References 51 publications

Dielectric Relaxation and Polaron Hopping in Cs₂AgBiBr₆ Halide Double Perovskites

Dielectric Relaxation and Polaron Hopping in Cs₂AgBiBr₆ Halide Double Perovskites

Microneedle‐Integrated Device for Transdermal Sampling and Analyses of Targeted Biomarkers

Doped Graphene Quantum Dots Modified Zn_0.9Cd_0.1Se for Improved Photoelectric Properties

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Effect of sulfur-doped graphene quantum dots incorporation on morphological, optical and electron transport properties of CH3NH3PbBr3 perovskite thin films

Cited by 21 publications

References 51 publications

Dielectric Relaxation and Polaron Hopping in Cs2AgBiBr6 Halide Double Perovskites

Dielectric Relaxation and Polaron Hopping in Cs2AgBiBr6 Halide Double Perovskites

Microneedle‐Integrated Device for Transdermal Sampling and Analyses of Targeted Biomarkers

Doped Graphene Quantum Dots Modified Zn0.9Cd0.1Se for Improved Photoelectric Properties

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Product

Resources

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Dielectric Relaxation and Polaron Hopping in Cs₂AgBiBr₆ Halide Double Perovskites

Dielectric Relaxation and Polaron Hopping in Cs₂AgBiBr₆ Halide Double Perovskites

Doped Graphene Quantum Dots Modified Zn_0.9Cd_0.1Se for Improved Photoelectric Properties