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Absorption and transmittance of macroporous silicon and nanowires are calculated using the proposed analytical model. The analytical model takes into account the absorption and transmission of the macroporous layer and the monocrystalline substrate. The influence of the pore volume fraction and pore depth on the absorption and transmittance of macroporous silicon is calculated. The macroporous layer and the nanowire layer are considered as an effective medium. The structured surfaces of the macroporous layer are considered as Lambert surfaces. Absorption and transmittance of macroporous silicon and silicon nanowires are calculated according to formulas found analytically. Reflection from the surfaces of macroporous silicon affects the absorption, transmission, and trapping of light by the macroporous silicon. The absorption of macroporous silicon increases with an increase in the volume fraction of pores, due to a decrease in the effective refractive index of the macroporous silicon layer. The absorption of macroporous silicon begins to decrease at high pore volume fraction due to the increase in reflection from the boundary of the layer of macroporous silicon with a monocrystalline substrate. The absorption spectrum of macroporous silicon does not depend on the pore depth when the pore volume fraction is less than 0.25. The transmittance of macroporous silicon increases with an increase in the volume fraction of pores in relation to single crystal silicon. An increase in the thickness of the macroporous silicon and a decrease in the thickness of the monocristalline substrate lead to an increase in the transmittance of macroporous silicon. [ABSTRACT FROM AUTHOR]

Mid-wavelength InSb and HgCdTe photodiodes (PDs) passivated with polycrystalline CdTe films have been studied. Passivating layers were deposited at low temperatures by the hot-wall epitaxy (HWE) technique. The PDs were characterized by measurements of the dark current and minority carrier lifetime. It is shown that heterovalent and isovalent (CdTe/InSb and CdTe/HgCdTe) interfaces have different effects on the PD characteristics. Passivation of HgCdTe does not affect the lifetime of the carriers, but the stability of the dark current in passivated PDs is insufficient for long-term operation. In the InSb PDs, the processing steps, including successive etching in CP4A and HCl etchants, sulfidization in an aqueous solution of Na2S, followed by the deposition of a protective CdTe layer, led to the best result. It has been established that the electrical properties of the passivating layers of polycrystalline CdTe are determined by the space charge-limited current. Conclusions are drawn about the applicability of the HWE technique for the passivation of infrared photodetectors. [ABSTRACT FROM AUTHOR]

The paper presents the theory and calculation of transmission, reflection, and absorption of macroporous silicon with through pores. Macroporous silicon with through pores is considered as an effective medium, the surface of which scatters electromagnetic waves. Scattering by the surface of macroporous silicon is taken into account using the effective scattering angle. The effective complex refractive index and the effective absorption coefficient are calculated using the mixing formulas. Derived analytical formulas for calculating transmittance, reflection and absorption of macroporous silicon with through pores take into account multiple reflections from the inner sides of the front and back surfaces. The influence of the volume fraction of pores and the thickness of macroporous silicon with through-pores on its reflection, transmission, and absorption was analyzed. The reflection and transmittance of the front and back surfaces and the absorption by the effective volume of macroporous silicon depend on the volume fraction of pores and affect the optical properties of macroporous silicon with through pores. [ABSTRACT FROM AUTHOR]

The kinetics of charge carriers in bilateral macroporous silicon with macroporous layers of equal thicknesses is calculated by the finite difference method. A diffusion equation for a monocrystalline substrate and macroporous layers is solved. The boundary conditions are defined at the boundaries between the monocrystalline substrate and the macroporous silicon layers on both sides. Stationary distribution of excess charge carriers in the bilateral macroporous silicon with the macroporous layers of equal thicknesses calculated by the finite difference method is set as the initial condition. Under stationary conditions, excess charge carriers are generated by light with the wavelengths of 0.95 μm and 1.05 μm. It is shown that at the counting times much longer than the relaxation time, all the distributions of the concentration of excess minority carriers generated by light with any wavelength approach the same distribution with exponentially decreasing value. [ABSTRACT FROM AUTHOR]

Some technological features of p-type Hg1-xCdxTe (x ≈ 0.3) liquid phase epitaxy layers grown on Cd1-yZnyTe (y ≈ 0.04) substrates are briefly discussed. Energy dispersive analysis of mercury-cadmium-telluride (MCT) layers and metal contacts (Au(In)/Cr(Mo,Ti)) to MCT layers together with their current-voltage characteristics at T ≈ 80 and 300 K are considered. It is shown that Cr(Mo,Ti)/MCT contacts have ohmic characteristics or close to them at T ≈ 80 and 300 K for both n- and p-type MCT layers. This gives the opportunity to form ohmic contacts to n- and p-type pads in one technological cycle. The contact resistance Rc is much smaller as compared to the HgCdTe p-n junction resistance R0[ RcA (< 10–2 Ω cm2) ≪ R0A (> 103 Ω cm2), where R0 is the zero bias diode resistance at T = 80 K, and A is the MCT (x ≈ 0.3) junction area]. So, such contacts are appropriate for the fabrication of photovoltaic HgCdTe detectors. [ABSTRACT FROM AUTHOR]

This study describes the clinical and microbiological features associated with group B Streptococcus (GBS) bone and joint infections (BJIs). It was a retrospective analysis of adult cases of GBS BJIs reported to the French National Reference Center for Streptococci from January 2004 to December 2014. Clinical data and GBS molecular characteristics are reported. Strains were collected from 163 patients. The most frequent comorbidities were: solid organ cancer ( n = 21, 21%) and diabetes mellitus ( n = 20, 20%). The main infection sites were knee (47/155 = 30%) and hip (43/155 = 27%), and occurred on orthopedic devices in 71/148 cases (48%). CPS III ( n = 47, 29%), Ia ( n = 26, 16%) and V ( n = 40, 25%) were predominant. Resistance to erythromycin, clindamycin and tetracycline was detected in 55/163 (34%), 35/163 (21%) and 132/163 (81%) strains, respectively. The most frequent sequence types were ST-1 ( n = 21, 25%), ST-17 ( n = 17, 20%) and ST-23 ( n = 11, 13%). The rate of resistance to erythromycin was 0% for ST-17 strains, 52% ( n = 11) for ST-1 and 44% ( n = 7) for ST-23 ( p < 0.001). GBS bone and joint infections predominantly occur in patients aged >50 years and/or with comorbidities such as cancer and diabetes mellitus. CPS type distribution and MLST are very similar to that of other adult GBS invasive infections. [ABSTRACT FROM AUTHOR]

We examined the significance of IgM peaks in chronic lymphocytic leukemia (CLL), including its association with newly reported MYD88, BIRC3, NOTCH1 and SF3B1 mutations. A total of 27, 25, 41 and 57 patients with monoclonal IgM or IgG peaks (IgM and IgG groups), hypogammaglobulinemia (Hypo-γ group) and normal immunoglobulin serum levels (normal-γ group) were, respectively, included. IgM peaks were mainly associated with Binet stage C and the del(17p). Biased usage of IGHV3-48 was shared by both IgM and IgG groups. IGHV3-74 and IGHV4-39 gene rearrangements were specific for IgM and IgG peaks, respectively. SF3B1, NOTCH1, MYD88 and BIRC3 mutation frequencies were 12%, 4%, 2% and 2%, respectively, being over-represented in IgM, IgG and Hypo-γ groups for SF3B1, and being equal between normal-γ and IgM groups for MYD88. Overall, 76%, 87%, 49% and 42% of cases from IgM, IgG, Hypo-γ and normal-γ groups had at least one intermediate or poor prognosis genetic marker, respectively. By multivariate analysis, IgM peaks were associated with shorter treatment-free survival independently from any other univariate poor prognosis biological parameters, including IgG peaks, Hypo-γ, IGHV status, SF3B1 mutations, cytogenetics and lymphocytosis. Therefore, as with IgG peaks, IgM peaks aggravated the natural course of CLL, with increased accumulation of adverse genetic events. [ABSTRACT FROM AUTHOR]