Highly Efficient and Broadband Hybrid Photodetector Based on 2-D Layered Graphene/CTS Quantum Dots

Oxidized eutectic gallium–indium (EGaIn) nanoparticles for broadband light response in a graphene-based photodetector

“…A time constant of about 3 ms is obtained, which is at least one order of magnitude faster than that of generally reported hybrid graphene-quantum dot photodetector. [25][26][27] The detectivity is also measured and calculated, and its value is about 3.8×10 9 cmHz 1/2 W -1 .…”

“…[22][23][24] However, the discrete energy structure of quantum dots makes its light absorption band narrow, which has limits for broadband detection. There is some work to improve the response of quantum-dot based devices, [25][26][27] but the performance in responsivity, response speed and response band generally cannot be optimized at the same time, and designed complex structure also increase difficulty for the fabrication and application, so much efforts is still needed.…”

CTS Quantum Dots–ZnO Nanocomposites for Broadband Photodetection

“…Single-atom thick materials such as graphene-based devices can be used as potential broadband PDs due to their high mobility (∼100,000 cm 2 /V s) and uniform absorption for the broad spectrum, but the low absorption (∼2.3%) of light leads to poor sensitivity and responsivity of the fabricated devices. , The alternative way to facilitate broadband photodetection is to form the hybrid structure of different materials having high absorption in UV, visible, and NIR regions. The hybrid structures of materials along with their nanocomposites, like quantum dots (QDs), nanowires, etc., have been used to improve the bandwidth, responsivity, sensitivity, and detectivity of the device. − Recently, the realization of broadband photodetection with high absorption QD structures has significantly attracted the researchers due to their superior optoelectronic characteristics. ,, QDs are the nanostructures where all the dimensions are in the nanoscale and the motion of the carriers is confined in all nanoscale regions. The confinement effects in the QD structure lead to discretization in the energy levels, that is, in conduction and valance bands, unlike bulk materials in their electronic structures.…”

“…This discretization in the energy levels in the QD structure facilitates multiple carrier transition under broad light illumination. Apart from the multiple wavelength signal absorption and emission, the band gap of the QDs can be easily varied by tuning their sizes . Size-dependent band gap tunability of the QD structure along with a high absorption coefficient makes them a potential contender for broadband photodetection along with various applications including bioimaging, drug delivery, and cancer treatment.…”

“…Similarly, Cu 2 SnS 3 (CTS) is earth-abundant, inexpensive, and band-gap-tunable with the size of QDs, which is a p-type semiconductor with a high absorption coefficient of ∼10,000 cm –1 in the vis–NIR region; therefore, it is a very good choice to be coupled with ZnO to fabricate a broadband PD for the UV–vis–NIR spectrum. CTS QDs are newly explored potential active nanomaterials for the vis–NIR band and have been explored in the present study due to their nontoxicity, low-cost solvothermal synthesis, large band gap tunability (0.93–1.77 eV), and good thermal stability as compared to widely used QD structures like PbS, PbSe, CdTe, HgTe, etc. ,, The various reports on CTS materials have been explored to study the atomic structure and its favorable optoelectronic properties including the high absorption coefficient. , The optical performance of the CTS materials has been improved by employing various nanostructures from their bulk states like thin films. ,, The performance of thin-film structures has been further improved by realizing a QD geometry synthesized by low-cost chemical routes as reported in various studies. , Recently, various studies on CTS QDs and their hybrid structure have been explored with various high-mobility nanomaterials including graphene, ,,,, which show the potentiality of these materials and their QD structure due to their strong photodetection ability in the vis–NIR spectrum.…”