Solution Processable 1D Fullerene C₆₀ Crystals for Visible Spectrum Photodetectors

Abstract

Visible spectrum photodetector devices fabricated using molecular crystals of carbon C are reported. The devices operate efficiently, extending over and beyond the full visible light spectrum (300-710 nm) with a bias voltage tunable responsivity of 4 mA-0.5 mA W . Across this range of wavelengths, the noise equivalent power of these devices remains below 10 nW Hz , providing a detectivity of 10 Jones. The noise current in these devices is found to have a strong dependence on both bias voltage and frequency, varying by 4 orders of magnitude from 1 nA Hz to 0.1 pA Hz . The devices also display a near-linear dependence of photocurrent on light intensity over 4 orders of magnitude, providing a dynamic range approaching 80 dB. The 3 dB bandwidth of the devices is found to be above 10 Hz, while the 18 dB bandwidth exceeds 1 kHz. The transient photocurrents of the devices have a rise time of ≈50 µs and a long fall time of ≈4 ms. The spectral photocurrent of the devices is found to quench gradually with a reduction in temperature from ≈300 K and is fully quenched at temperatures below T ≈ 100 K. Upon reheating, the device performance is fully recovered.

Spatially Confined Growth of Fullerene to Super‐Long Crystalline Fibers in Supramolecular Gels for High‐Performance Photodetector

“…The quantum efficiency (QE), which determines the efficiency of electron transport and carrier collection of the device, was calculated to be 8.0 × 10 2 % by Equation (10) in the Supporting Information . Compared to the other C 60 ‐based devices, the device derived from a single pure C 60 crystalline fiber in this work showed superior responsivity and detectivity to some results from LLIP method and solvent‐assisted self‐assembly as shown in Table S2 (Supporting Information) . The photoresponse of C 60 fibers with different diameters is shown in Figure S22 (Supporting Information).…”

“…The light power intensity‐dependent photocurrent curve shown in the inset can be fitted with a power law I p ∼ P θ , where I p and P stand for the photocurrent and the intensity of incident light, respectively. The exponent θ is calculated to be 0.90 (0.5 < θ < 1) over fitting, which is closely related to the process of electron–hole generation, separation, trapping, and recombination in a semiconductor . In particular, the fact that the θ is near to 1 indicates that photocurrent was nearly linear to the light intensity, fewer defects were existed in the C 60 crystal, and the crystalline quality of the C 60 crystalline fibers growing in supramolecular gels was excellent.…”

Rubrene-Directed Structural Transformation of Fullerene (C60) Microsheets to Nanorod Arrays with Enhanced Photoelectrochemical Properties

“…Even so, the orthorhombic rubrene still exists in the hcp structured C 60 microsheets (denoted as hcp 2, Figure S12). Both C 60 and rubrene are organic molecules with π-conjugated systems, showing great potential in the field of optoelectronics [55][56][57]. Therefore, we measured the photocurrent response curves of thin films on ITO glasses composed of C 60 MSs, C 60 NRs, and C 60 -RNRAs to explore their photoelectrochemical properties.…”

Room‐Temperature Crystallization of Ultralong (≈3.5 mm) CsCu2I3 Microbelt to Suppress Carrier Recombination for High‐Performance UV Heterojunction Photodetector

“…This nonunity power law index is associated to the complex process of the generation, capture, transfer, and recombination of electrons and holes in the photoresponse process for the CsCu 2 I 3 microbelt-based photodetector. [33] The photodensity-dependent photoresponse reveals the existence of various shallow and deep traps with different energy levels in the bandgap. The higher value θ of 0.75 at reverse bias voltage of −3 V indicates better photoelectric conversion efficiency than that at forward bias voltage of 3 V, and this result is corresponding to higher switch ratio and lower dark current at reverse bias voltage of 3 V. As shown in Figure S5c in the Supporting Information, a higher value θ of 0.77 is obtained in pure CsCu 2 I 3 microbelt photodetector, which may be attributed to less interface loss of photogenerated carriers.…”