Self-powered, flexible, and ultrabroadband ultraviolet-terahertz photodetector based on a laser-reduced graphene oxide/CsPbBr₃ composite

Abstract

Self-powered and flexible ultrabroadband photodetectors (PDs) are desirable in a wide range of applications. The current PDs based on the photothermoelectric (PTE) effect have realized broadband photodetection. However, most of them express low photoresponse and lack of flexibility. In this work, high-performance, self-powered, and flexible PTE PDs based on laser-scribed reduced graphene oxide ( LSG ) / CsPbBr 3 are developed. The comparison experiment with LSG PD and fundamental electric properties show that the LSG / CsPbBr 3 device exhibits enhanced ultrabroadband photodetection performance covering ultraviolet to terahertz range with high photoresponsivity of 100 mA/W for 405 nm and 10 mA/W for 118 μm at zero bias voltage, respectively. A response time of 18 ms and flexible experiment are also acquired at room temperature. Moreover, the PTE effect is fully discussed in the LSG / CsPbBr 3 device. This work demonstrates that LSG / CsPbBr 3 is a promising candidate for the construction of high-performance, flexible, and self-powered ultrabroadband PDs at room temperature.

Photoreduction-Insensitive GO/rGO Patterning Based on Multistep Femtosecond Laser Writing for Implementing Fresnel Zone Plates

“…Femtosecond laser (fs-laser)-induced micro/nanopatterning of reduced graphene oxide (rGO), accompanying in situ photoreductions, has garnered considerable attention because its properties can be effectively adjusted using a facile and maskless method. − GO/rGO-based micro/nanostructures with mechanical flexibility, chemical/physical stability, and optical and electrical property tunability have been used in various applications, such as diffractive lenses, supercapacitors, photodetectors, and actuators. ,− With the removal of oxygen and carbon atoms, the patterning linewidth and photoreduction degree of GO/rGO are adjustable by controlling the fs-laser parameters encompassing the pulse energy and repetition rate. ,− At present, the most adopted technology for the photoreduction of GO via an fs-laser is direct writing based on a single-exposure process . However, when this method is used for enhancing the photoreduction degrees of GO/rGO, the side effect of the corresponding patterning linewidth widening becomes too obvious to be ignored. − The co-occurrence of tailoring the patterning linewidth and degrees of photoreduction hinders the application of fs-laser-induced GO/rGO patterning. ,− When the desired optical transmission, film thickness, and electrical conductivity come from high or medium degrees of GO/rGO photoreduction, it is unreasonable to expect to employ the minimum linewidth that can only be achievable at the lowest degree of photoreduction.…”

Role of the Optical–Acoustic Phonon Interaction in the Ultrafast Cooling Process of CVD Graphene

“…This is expected to be the main mechanism of the relaxation process and is likely to cause the phonon recycling and Zener–Klein tunneling processes, which have been presented in recent publications. , Thus, more efficient cooling is expected to occur in highly doped graphene with a higher degree of disorder. This finding suggests a new approach for hot electron dynamics applications in thermal and phonon transistors and terahertz high-harmonic generation devices. , …”

“…This finding suggests a new approach for hot electron dynamics applications in thermal and phonon transistors and terahertz high-harmonic generation devices. 33,34 ■ CONCLUSIONS In this study, the terahertz relaxation dynamics in CVD graphene were systematically investigated. By generating an initial hot electron energy lower than the minimum optical phonon energy, we find that the electron−optical phonon…”

Organic Ternary Bulk Heterojunction Broadband Photodetectors Based on Nonfullerene Acceptors with a Spectral Response Range from 200 to 1050 nm

“…Another important parameter of the OPD is D *, which determines the ability of the fabricated OPD for detecting weak light signals. D * can be determined by using the following formula: where R λ is the responsivity at the wavelength λ, A is the effective illuminated area of the OPD (8.25 × 10 –4 cm 2 ), q is the electron charge, and I dark is the dark current. The D * values at 7 V of the ZnO/Au/PEDOT:PSS/P3HT:PC61BM BHJ OPD and ZnO/Au/PEDOT:PSS/P3HT:PC61BM:Ir-125 BHJ OPD can reach 3.62 × 10 12 Jones and 9.07 × 10 12 Jones, respectively.…”