The aim of this study is to analyze the prognostic value of androgen receptor (AR) expression for patients with triple-negative breast cancer (TNBC). Clinical data of these patients were collected and analyzed, and immunohistochemical staining for AR was performed on tissue microarrays of operable breast cancer from 287 patients with TNBC, who were treated at Sun Yat-sen University Cancer Center from January 1995 to December 2008. AR expression was found in 25.8% of the cases with TNBC. TNBC patients with AR negative have a higher proportion of positive lymph node. A significant correlation was found between AR expression and disease-free survival (DFS) and overall survival (OS). Univariated analysis indicated that AR expression had a significant prognostic value in TNBC patients, whereas multivariate analysis indicated that AR was a significant independent prognostic factor of DFS (P = 0.032) in all patients. Our results suggested that AR was a favorable prognostic factor of DFS and OS in patients with TNBC. Therefore, TNBC may be further divided into two subtypes according to AR status.

In polycrystalline thin films, the inherent grain boundaries that contain abundant charge traps can cause adverse effect on optoelectronic properties of perovskite materials, and defect passivation is necessary for efficient polycrystalline PSCs. [3] In contrast, perovskite single crystals offer an opportunity to further improve the efficiency of PSCs, due to the absence of grain boundaries as well as their orders of magnitude lower defect density and longer carrier diffusion length than those in their polycrystalline counterparts. [4] Recently, the efficiency of smallarea single-crystal PSCs based on 20 µm thick MAPbI 3 (MA = CH 3 NH 3 + ) absorber layer has reached 21.9% by using a low-temperature (<90 °C) inverse temperature crystallization (ITC) method. [5] Moreover, the near-infrared response of the devices can be expanded by incorporating FA (FA = CH(NH 2 ) 2 + ) into MAPbI 3 crystals, leading to a high PCE of up to 22.8%. [6] To construct large-area single-crystal PSCs, Liu et al. developed a refreshing-reiteration method to grow perovskite bulk single crystals with dimension as large as 120 mm. [7] Besides, they established a diamond-wire-sawing process to produce inchsized single-crystal perovskite wafers for fabrication of inchsized single-crystal PSCs. [8] For photovoltaic application, growth of micrometer-thick lead-iodide perovskite single crystals is necessary to promote carrier transport and collection. [9] Liu et al. designed an ultrathin geometry-defined dynamic-flow reaction system and realized the growth of large-area single-crystal perovskite wafers with controllable thickness, which provides a universal and effective strategy for application of perovskite single crystals in optoelectronic device design and fabrication. [10] In this method, a mass concentration of defects would unavoidably be generated at the interface due to the lattice mismatch between perovskite and hole transport layer (HTL). Huang et al. found that the trap density in perovskite single crystals increased by five orders of magnitude from interior to surface/interface, and most deep traps were detected near the HTL/perovskites interface. [11] On the other hand, the ion diffusion rate in the confined space is limited by the interaction between substrates and solvated Perovskite single crystals have recently been regarded as emerging candidates for photovoltaic application due to their improved optoelectronic properties and stability compared to their polycrystalline counterparts. However, high interface and bulk trap density in micrometer-thick thin single crystals strengthen unfavorable nonradiative recombination, leading to large open-circuit voltage (V OC ) and energy loss. Herein, hydrophobic poly(3-hexylthiophene) (P3HT) molecule is incorporated into a hole transport layer to interact with undercoordinated Pb 2+ and promote ion diffusion in a confined space, resulting in higher-quality thin single crystals with reduced interface and bulk defect density, suppressed nonradiative recombination, accelerated charge transp...

No abstract

Self‐powered perovskite X‐ray detectors have drawn increasing attention due to the merits of low noise, low power consumption as well as high portability and adaptability. However, the active layer thickness is usually compromised by the small carrier diffusion length, which leads to inefficient X‐ray attenuation and hence low sensitivity of the detectors. Herein, self‐powered and highly sensitive single‐crystal perovskite X‐ray detectors are achieved by finely controlling the crystal thickness and optimizing their carrier transport properties. Perovskite single crystals with thickness of around 800 µm are grown by a two‐step crystal growth process to realize the full attenuation of hard X‐ray with the energy of 80 keV. And the incorporation of formamidinium (FA) (FA = CH(NH2)2+) cation into methylammonium lead triiodide (MAPbI3) (MA = CH3NH3+) increases the mobility‐lifetime (µτ) product of the single crystals by nearly one order of magnitude, leading to a record X‐ray detection sensitivity of 8.7 × 104 µC Gyair−1 cm−2 under zero bias. Moreover, the eliminated external bias and reduced trap density weaken the field‐driven ion migration effect, and therefore result in a low detection limit of 27.7 nGy s−1. This work represents an effective way to achieve self‐powered perovskite X‐ray detectors with both high sensitivity and low detection limit.

Organic–inorganic halide single-crystal perovskite solar cells (PSCs) are promising for higher efficiency and better stability, but their development lags far behind that of their polycrystalline counterparts. In particular, the low efficiency (<5%) of large-area devices makes the development of an alternative perovskite photovoltaic technology challenging. In this Perspective, we highlight that the optimization of crystal growth and reduction of crystal thickness are keys to improving the performance of the large-area single-crystal PSCs. After analyzing the characteristics of perovskite crystal growth methods and efficiency evolution of single-crystal PSCs, we conclude the low efficiency of large-area devices is due to the conflict between low crystal quality and large crystal thickness. Then, we propose methods to grow high-quality perovskite single crystals and a possible strategy to reduce the crystal thickness. Finally, investigation of key factors and exploration of large-area application are suggested to be conducted in parallel for future development of single-crystal PSCs.