Tunable ionic conductivity and photoluminescence in quasi-2D CH₃NH₃PbBr₃ thin films incorporating sulphur doped graphene quantum dots

Abstract

Ion migration in hybrid halide perovskites is ubiquitous in all conditions. However, ionic conductivity can be manipulated by changing the material composition, operating temperature, light illumination, applied bias as well...

Tuning Conductivity of Lead-Free Cs2AgBiBr6 Double Perovskite Ternary Composite with PEDOT:PSS and Carbon Black for Supercapacitor Application

“…To elucidate the electronic and ionic charge carrier dynamics in perovskite electrodes, the AC conductivity has been determined by the imaginary part of the complex permittivity, ε″(ω), according to σ ( ω ) = ω n ε 0 ε ″ where ω is the angular frequency, ε 0 is the free space permittivity, and ε″ is the imaginary part of the complex dielectric constant of the sample, while exponent n is any value from 0 to 1 (see SI Figure S11). The imaginary part of the complex permittivity, ε″(ω), that is associated with the dissipation of energy during the application of electric field as polarization can be calculated from the impedance spectra according to ε ″ ( ω ) = Z ′ ω C 0 ( Z ′ 2 + Z ″ 2 ) Here C 0 (= ε 0 A / d ) is the free space capacitance, A (1 cm × 1 cm) is the active area of the electrode, and d is the thickness of active material coated on electrode (∼10 –6 m). Figure d–f illustrate two distinct frequency-dependent regions of ionic conductivity, observed in the frequency range from 10 mHz to 1 MHz.…”

“…where ω is the angular frequency, ε 0 is the free space permittivity, and ε″ is the imaginary part of the complex dielectric constant of the sample, while exponent n is any value from 0 to 1 (see SI Figure S11). 34 The imaginary part of the complex permittivity, ε″(ω), that is associated with the dissipation of energy during the application of electric field as polarization can be calculated from the impedance spectra according to…”

Hybrid Halide Perovskite‐Based Electrochemical Supercapacitors: Recent Progress and Perspective

“…composition, electron and hole transport materials, crystal structure, as well as defect density of states, light, heat, and the electric field. [14,52,53] This ion migration plays a very crucial role in the charge/energy storage mechanism. [21] Photoinduced ion migration in the perovskite active electrodes can modulate the total charge/ energy storage (Table 1).…”

“…It has been observed that ion migration in these devices is unpredictable due to various intrinsic as well as extrinsic parameters affecting ion kinetics, such as perovskite composition, electron and hole transport materials, crystal structure, as well as defect density of states, light, heat, and the electric field. [ 14,52,53 ] This ion migration plays a very crucial role in the charge/energy storage mechanism. [ 21 ] Photoinduced ion migration in the perovskite active electrodes can modulate the total charge/energy storage (Table 1).…”

Electronic-Ionic Transport in MAPbBr3 Single Crystal: The Evidence of Super-Linear Power Law in AC Conductivity

“…Apart from these, MHPs have recently attracted much attention as active layers for field-effect transistors (FETs), high-energy radiation detectors (X-ray and γ-ray), and imaging devices for medical diagnostics. MHPs show intriguing properties, including strong light absorption, high photoluminescence quantum yields (PLQYs), high color purity, , tunable energy band gap, − high charge carrier mobility, long exciton lifetime, significant X-ray attenuation coefficient, and low exciton binding energy. For polycrystalline perovskite solar cells (PSCs), power conversion efficiencies (PCEs) of almost 25.5% have been achieved over a short period, and a similar trend is being observed for perovskite-based light-emitting diodes (PeLEDs). , The major stumbling blocks of polycrystalline perovskite thin-film devices (PTFDs) are the formation of surface defects upon rapid crystallization and many grain boundaries.…”