We synthesize a vertical heterostructure (HS) between tin sulfide (SnS) and molybdenum sulfide (MoS2) by chemical vapor deposition based on the preferential adsorption of sulfur on MoS2. Most of the SnS grains nucleate on MoS2 nanosheets, formatting partially stacked HS with large overlapping regions. Photoluminescence quenching of MoS2 is observed and illustrates effective charge separation in HS. The HS shows increased reverse saturable absorption relative to MoS2 and SnS. The preferential adsorption of sulfur powders on MoS2 and HS growth reported herein will provide a promising approach to the synthesis of other two-dimensional HS.

The construction of p–n junctions is necessitated by applications which require effective charge separation. Here, a novel heterostructure (HS) of molybdenum sulfide (MoS2) and copper sulfide (Cu2–x S) was synthesized by chemical vapor deposition, with Cu2–x S nanoparticles vertically stacked on a MoS2 nanosheet. A well-defined epitaxial relationship between MoS2 and Cu2–x S is established, although the corresponding lattice mismatch is as large as 20%. The band-edge alignment is experimentally determined, indicating that the MoS2–Cu2–x S HS is a type II heterojunction. Photoluminescence quenching indicates effective charge separation in HS. The resultant HS shows enhanced nonlinear absorption in comparison with single-component MoS2 nanosheets and Cu2–x S nanoparticles.

The electrical tuning of the nonlinear absorption of materials has promising application potential, while studies remain rare. In this work, we show that the third-order nonlinear absorption of poly(3,4-ethylenedioxythiophene) chemically doped with poly(styrene sulfonic acid) [PEDOT:PSS] can be effectively modulated by external voltage. The 2 nonlinear absorption of the film can be varied between reverse saturable absorption (RSA) and saturable absorption (SA) via voltage control with laser excitation at 800 nm, and corresponding nonlinear absorption coefficient can be tuned in the range -1590 to 518 cm GW -1 . The doping level and energy structure of PEDOT are modulated with different voltages. The undoped film affords two-photon absorption and accordingly the RSA response. A moderately doped sample has two polaron levels, and Pauli blocking associated with these two polaron levels results in SA. The bipolaron level in heavily doped PEDOT leads to excited state absorption and therefore RSA behavior.The approach reported here can be applied to other semiconductors, being a convenient, effective, and promising method for the electrical tuning of the optical nonlinearity.

Herein it is reported that electrochemical ion-intercalation is a convenient and effective strategy toward materials with giant nonlinear optical (NLO) absorption. Alkali-metal ions (i.e., Li + , Na + , K + ) are electrochemically intercalated into SnS 2 nanosheets. All ion-intercalated samples exhibit remarkably enhanced optical nonlinearity compared with an untreated sample, and Liintercalated SnS 2 (Li 0.952 Sn II 0.398 Sn IV 0.563 S 2 ) possesses optimized strong NLO performance. Li 0.952 Sn II 0.398 Sn IV 0.563 S 2 exhibits strong saturable absorption, and the corresponding nonlinear absorption coefficient (β eff ) is -1.7 × 10 4 cm GW -1 for the laser excitation at 515 nm. Li 0.952 Sn II 0.398 Sn IV 0.563 S 2shows prominent reverse saturable absorption with the laser excitation at 800 nm (β eff : 2.8 × 10 4 cm GW -1 ) and 1030 nm (β eff : 1.4 × 10 4 cm GW -1 ). All β eff values are larger than most of the reported inorganic NLO materials at corresponding wavelengths. The optical limiting threshold of Li 0.952 Sn II 0.398 Sn IV 0.563 S 2 is 8 × 10 -4 J cm -2 , two orders of magnitude smaller (better) than the benchmark composite (e.g., SWNT-NH-TPP). Ion intercalation introduces abundant in-gap defects. The excitation of electrons in in-gap states to conduction band intensifies the Pauli-blocking effect and therefore promotes the saturable absorption under the 515 nm laser excitation, while the in-gap defect states acting as effective excitation pathway facilitate excited-state absorption for 800 and 1030 nm laser.

Rationale:Clear cell renal cell carcinoma (CCRCC) is an aggressive tumor associated with a high risk of metastasis and very low survival rate. In addition, it can cause extensive blood metastasis to the lungs, bones, and other organs. Chest wall metastatic tumors from primary CCRCC are rare.Patient concerns:In this report, we present a case of metastatic chest wall tumor that originated from a CCRCC.Diagnoses:An 86-year-old man was diagnosed with chest wall tumor using chest computed tomography. After collecting tissues from the chest wall tumor via needle biopsy, the pathological examination was combined with positive immunoreaction of CD10, epithelial membrane antigen, and vimentin, and the patient was diagnosed with metastatic CCRCC in the chest wall deposits.Interventions:The patient received radiotherapy at 2.0 Gy per time for 25 times.Outcomes:Following 2 months of treatment, the chest wall tumor had shrunk by about one-third of its size.Lessons:Our patient developed a metastatic chest wall tumor that originated from a CCRCC for which right nephrectomy had been performed 10 years previously. Although as per the literature, chest wall metastasis from CCRCC is very rare, it is important to consider tumor metastasis after several years of treatment for precise diagnosis and proper treatment.