Publications by authors named "Songyang Yuan"

Despite CsPbIBr inorganic perovskites exhibit high potential for single-junction and/or tandem solar cells, unexpected non-radiative recombination, and mismatched interfacial band alignment within the inorganic perovskite solar cells (PSCs) disadvantageously affect their photovoltaic performance. Rational design of the dipole shielding layer (DSL) is vital to realize a win-win situation for the defect passivation and band alignment. Herein, A-site dipole molecules, that is, neopentylamine and 2-methylbutylamine, are employed for in-situ self-assembly of a thus-far unreported DSL at the interface between 3D perovskite and hole transport layer.

View Article and Find Full Text PDF

Lead-free inorganic perovskites have attracted intensive attention in the field of photodetectors owing to their high stability, non-toxicity, and remarkable photoelectric characteristics. Herein, we designed and developed a series of thus-far unreported lead-free all inorganic perovskite single crystals, KBiX (X = Cl, Br). In particular, we resorted to cooling crystallization and intercalated K to inorganic Bi-Br and Bi-Cl frameworks as inorganic A-site cations, obtaining zero-dimensional (0D) KBiX (X = Cl, Br) perovskite single crystals, which display suitable bandgaps, excellent electron mobility and low trap-state density, as analysed by experimental characterization and density functional theory (DFT) calculations.

View Article and Find Full Text PDF

Low-dimensional perovskites (LDPs) have enormous potential for the development of advanced optoelectronic devices and tackling the stability issue for the commercial application of perovskites. However, quantified structural dimensionality prediction for LDPs is still an intractable issue. Herein, we develop a self-established machine learning (ML)-assisted approach to predict the dimensionality of LDPs based on 195 reported amines that are classified as two-dimensional, one-dimensional, and zero-dimensional.

View Article and Find Full Text PDF

Low-dimensional organic-inorganic hybrid perovskites (OIHPs) with broadband emission attract immense scientific interest due to their potential application for the next generation of solid-state lighting. However, due to low exciton utilization, organic cations generally adjust structure rather than contribute the band edge to affect optical properties. Based on this, OIHPs are usually allowed to obtain a low photoluminescence quantum yield (PLQY).

View Article and Find Full Text PDF

A series of novel perovskite single crystals are innovatively grown. Aiming to enhance the luminescence performance, octahedral distortion co-regulation via dual strategies for the as-prepared perovskite single crystals is performed. The distortion of the octahedral structure strengthens the electron-phonon coupling and electron localization, resulting in a more stable self-trapped state, which thereby increases the potential for radiative recombination, accompanied by the self-trapped exciton emission.

View Article and Find Full Text PDF

Multidimensional perovskite techniques are of intense research interest since they are proved to be advantageous to enhance the perovskite stability. Thereinto, the structure engineering strategy has been widely used to regulate the low dimensional (LD) perovskite structures and obtain expected optoelectronic properties. In this work, we intercalate a thus far unreported metallic coordination compound [Ga-Tpy] (Tpy: 2,2';6',2″-terpyridine) to the inorganic Pb-I building block as the A-site organic group, and the zero dimensional (0D) [Ga-Tpy]PbI perovskite-like single crystal is obtained.

View Article and Find Full Text PDF

Despite the rapid development of CsPbI Br (0 ≤ x ≤ 3) inorganic perovskite solar cells, associated with their superior thermal stability, their low moisture stability limits their commercial deployment. In this study, 1D-2D-3D multidimensional coupled perovskites are prepared by means of an in situ self-integration approach. This pioneering method allows incorporating thus far unreported 1D-Tpy Pb I and 2D-TpyPb I (Tpy; terpyridine) perovskites.

View Article and Find Full Text PDF

Lead-free double perovskites have attracted noteworthy attention due to their compositional flexibility and electronic diversity. In this study, we hydrothermally grow a new class of CsAgNaFeCl (0 ≤ ≤ 1) perovskite single crystals with high thermal stability. The substitution of B-site cation allows to regulate the crystallographic and band structure, which gives rise to enlarged band absorbance close to the near-infrared region (∼800 nm) via composition engineering.

View Article and Find Full Text PDF

Cutaneous angiomyolipoma is a rare mesenchymal tumor, distinct from its renal counterpart. Only few cases have been reported in English language literature to date. Here, we report a case in a 36-year-old man who presented with a painless swelling on his right ear.

View Article and Find Full Text PDF

Aims: Gastric heterotopia (GH) has been described throughout the gastrointestinal tract. However, the colorectal region is an extremely rare location for it. We describe the clinicopathological features of GH of the colon, rectum and anus.

View Article and Find Full Text PDF

Gender confirmation surgery is increasingly common in persons with gender dysphoria. We describe changes seen in gonads from individuals seeking male-to-female physical adaptation. We studied 99 orchiectomies from 50 persons.

View Article and Find Full Text PDF

Three sporadic, synchronous, and separate lesions in the ampulla of Vater and the head of the pancreas presented in an 81-year-old male. One was symptomatic and two were incidental. One was detected preoperatively (the ampullary lesion) and two by examination of the resected specimen (the neuroendocrine and pancreatic carcinomas).

View Article and Find Full Text PDF

Nocardia spp. can cause pulmonary infection, usually in the setting of immunosuppression or underlying lung disease. There have been a few reports of these organisms isolated from cystic fibrosis patients and, when recovered, the isolates were almost always Nocardia asteroides.

View Article and Find Full Text PDF

No single cytologic feature is specifically diagnostic for papillary thyroid carcinoma. We report herein the presence of swirl-like cellular aggregates in fine needle aspirates of papillary thyroid carcinoma but not in other thyroid entities. Cellular swirls are defined as concentrically organized aggregates of tumor cells in which many of the most peripherally situated cells have ovoid rather than round nuclei that are oriented perpendicular to the radius of the swirl.

View Article and Find Full Text PDF

Fine needle aspiration (FNA) biopsy is a useful tool in the diagnosis and management of suspicious masses. Most FNA biopsies of palpable masses can be performed without radioguidance by either clinicians or cytopathologists; however, it is unclear if there is a difference in the diagnostic yield of the procedure based on who performs the FNA. We reviewed the FNA biopsy results of 200 patients presenting with head and neck masses to a tertiary care center from 2003 to 2004.

View Article and Find Full Text PDF

Body cavity effusions may be the first manifestation of malignancy or of recurrence or relapse. We surveyed effusions and washes for expression of X-linked inhibitor of apoptosis (XIAP), a potent constituent of the inhibitor of apoptosis (IAP) family of proteins. IAPs prevent apoptosis by blocking the activation of caspases, thereby preventing caspase-mediated cell degradation.

View Article and Find Full Text PDF

The long-term outcome of human islet allotransplantation is poor, and it remains to be seen if the Edmonton Protocol will make a positive impact upon the extension of posttransplant islet function. Hence, establishing an implantation site capable of sustaining islet allografts for a prolonged duration needs to be explored. In this study we investigated the submucosal space of the duodenum in Syrian golden hamsters.

View Article and Find Full Text PDF