Search

CdSe semiconductor thin films were grown on indium tin oxide (ITO) coated glass substrates by co-electrochemical deposition method. Deposition potential was kept at - 0.95 V vs. Ag/AgCl reference electrode for ten minutes. Deposition electrolyte includes an aqueous solution of 10 mM CdCl2, 20 mM H(2)SeO(3 )as precursors, 200 mM LiCl as complexing agent, and HCl for adjusting of pH. Deposited CdSe thin film was annealed at 500 degrees C for 30 min in air medium. Precursor and annealed CdSe thin films were characterized using a number of techniques, including SEM, EDX, XRD, UV-vis spectroscopy, and electrochemical impedance spectroscopy. SEM studies show that annealing alters the surface of precursor CdSe film from smooth to granular appearance. According to EDX analyses, the ratio of Cd/Se is close to 1.07 and 1.04 for the precursor and annealed CdSe thin film, respectively. XRD analysis shows that each film has polycrystalline structure. Precursor film has only cubic structure of CdSe, while annealed film has hexagonal structure of CdSe and cubic crystal phase of CdO. Optical energy band gap of the as-deposited CdSe film increases from 1.64 to 1.71 eV after annealing due to the mixture of the two phases. Refractive index against wavelength changes between 2.0 and 3.3. Calculations performed by using the data of Mott-Schottky measurements show that precursor CdSe film has 1.72 x 10(16 )cm(-3), while annealed film is of 3.65 x 10(17 )cm(-3 )carrier concentration. The prepared films exhibit n-type semiconductor character. The study reports energy level diagrams of the produced semiconductor CdSe thin films by using the Mott-Schottky and Tauc's approximations. The carrier transport properties in the interface between active CdSe thin film and electrolyte are discussed based on an equivalent electronic circuit simulated to the Nyquist data of the CdSe/electrolyte system.

Aims : Invasive micropapillary carcinoma of the breast is an aggressive and distinctive variant of breast cancer. These tumours have a characteristic histological appearance and have been associated with a high incidence of axillary lymph node metastases and a poor clinical outcome. The aims of this study were to investigate the immunohistochemical profile of invasive micropapillary carcinoma of the breast, to compare it with invasive ductal carcinoma, and to identify the morphological parameters which predict its poor outcome. Methods and results : Fifty-three (2.6%) invasive micropapillary carcinomas of the breast from 2022 cases of infiltrating breast carcinomas were identified by retrospective review. The patient age at presentation ranged from 33 to 78 years (mean 52.5 years). The tumour size ranged from 5 to 70 mm (mean 27 mm). Eighty-two percent (43 of 53) were of high histological grade; 69% (33 of 48) of cases with axillary lymph node dissections had positive lymph nodes; and 75.5% (40 of 53) had lymphatic invasion: 46% (22 of 48) of cases had extranodal extension. Of lymph node-positive cases, 61% had four or more metastatic lymph nodes. Of tumours with tumour size >10 mm, 77% had positive lymph nodes. The percentages of cases positive for oestrogen receptor (ER) and progesterone receptor (PR) were 68% and 61%, respectively. These values were significantly higher than the values for invasive ductal carcinomas. p53 and c-erbB-2 were detected in 48% and 54% of cases, respectively. The mean value of Ki67 was 26%. Follow-up was available in 36 patients. Eight patients had local recurrences, nine patients had distant metastases, and 10 patients died of disease within a follow-up period of 9 years. Conclusion : Lymphotropism and an unfavourable prognosis are the hallmarks of this distinct entity. Prognostic markers such as ER, PR, p53, and c-erbB-2 failed to provide new criteria to allow discrimination of these tumours from other breast cancers.