W artykule przedstawiono wyniki badania związku aktywności wynalazczej przedsiębiorstw przemysłowych państw Grupy Wyszehradzkiej, mierzonej za pomocą liczby zgłoszeń do Europejskiego Urzędu Patentowego, z wielkością nakładów na badania i rozwój ponoszonych w obszarach działalności gospodarczej o różnym poziomie zaawansowania technicznego. Wyniki jedno- i wielorównaniowej analizy kointegracyjnej danych panelowych dla lat 2005–2014 wskazują, że długookresowa elastyczność liczby zgłoszeń patentowych względem nakładów na badania i rozwój jest wyższa, po pierwsze, w przypadku działalności w dziedzinie wysoko zaawansowanej techniki, niż w dziedzinie średniowysoko zaawansowanej techniki, po drugie, w dziedzinie wysoko zaawansowanej techniki dla aktywności badawczej finansowanej ze środków własnych, niż w przypadku badań finansowanych ze środków publicznych. Stwierdzono również, że w przypadku średnionisko i nisko zaawansowanej techniki, nakłady na badania i rozwój nie determinują jednoznacznie liczby zgłoszeń patentowych.

Small sample properties of unrestricted and restricted canonical correlation estimators of cointegrating vectors for panel vector autoregressive process are considered when the cross-sectional dependencies occur in the process generating nonstationary panel data. It is shown that the unrestricted Box-Tiao estimator is slightly outperformed by the unrestricted Johansen estimator if the dynamic properties of the underlying process are correctly specified. The comparison of performance of the restricted canonical correlation estimator of cointegrating vectors for the panel VAR and for the classical VAR applied independently for each cross-section reveals that the latter performs better in small samples when the cross-sectional dependence is limited to the error terms correlations, even though it is inefficient in the limit, but it falls short in comparison to the former when there are cross-sectional dependencies in the short-run dynamics and/or in the long-run adjustments.

We test whether the floating exchange rates of the EU New Member States against the euro are determined jointly within the panel VEC framework. We find that the exchange rates of the Czech koruna, the Polish zloty and the Hungarian forint follow the same long-run relationship, in which the real exchange rates are explained by the real interest rates parities and the spreads of the credit default risk premiums. In case of the Romanian leu, the common relationship is rejected, which is likely due to differences in the economic setting. The results confirm that the currency markets of these three countries are closely related, since the appreciation/depreciation of one currency leads to similar movements in the other currencies of the NMS. The estimated misalignments exhibit some common patterns in terms of time spans and percentage values of under/overvaluation.

In this work we report simulation and experimental results for an MWIR HgCdTe photodetector designed by computer simulation and fabricated in a joint laboratory run by VIGO Sytems S.A. and Military University of Technology. The device is based on a modified N+pP+ heterostructure grown on 2”., epiready, semi-insulating (100) GaAs substrates in a horizontal MOCVD AIX 200 reactor.

The devices were examined by measurements of spectral and time responses as a function of a bias voltage and operating temperatures. The time response was measured with an Optical Parametric Oscillator (OPO) as the source of ~25 ps pulses of infrared radiation, tuneable in a 1.55–16 μm spectral range. Two-stage Peltier cooled devices (230 K) with a 4.1 μm cut-off wavelength were characterized by 1.6 × 1012 cm Hz1/2/W peak detectivity and < 1 ns time constant for V > 500 mV.

The performance of HgCdTe barrier detectors with cut-off wavelengths up to 3.6 μm fabricated using metaloorganic chemi- cal vapour deposition operated at high temperatures is presented. The detectors’ architecture consists of four layers: cap contact, wide bandgap barrier, absorber and bottom contact layer. The structures were fabricated both with n- and p-type absorbing layers. In the paper, different design of cap-barrier structural unit (n-B_p′, n⁺-B_p′, p+-B_p) were analysed in terms of various electrical and optical properties of the detectors, such as dark current, current responsivity time constant and detectivity.

The devices with a p-type cap contact exhibit very low dark current densities in the range of (2÷3)×10^-4 A/cm² at 230 K and the maximum photoresponse of about 2 A/W in wide range of reverse bias voltage. The time constant of measured de- vices with n-type cap contact and p-type absorbing drops below 1 ns with reverse bias while the detectivity is at the level of 1010 cm ^∙ Hz1/2/W.

Non-intentionally doped GaSb epilayers were grown by molecular beam epitaxy (MBE) on highly mismatched semi-insulating GaAs substrate (001) with 2 offcut towards (110). The effects of substrate temperature and the Sb/Ga flux ratio on the crystalline quality, surface morphology and electrical properties were investigated by Nomarski optical microscopy, X-ray diffraction (XRD) and Hall measurements, respectively. Besides, differential Hall was used to investigate the hole concentration behaviour along the GaSb epilayer. It is found that the crystal quality, electrical properties and surface morphology are markedly dependent on the growth temperature and the group V/III flux ratio. Under the optimized parameters, we demonstrate a low hole concentration at very low growth temperature. Unfortunately, the layers grown at low temperature are characterized by wide FWHM and low Hall mobility.

We report on the status of long-wave infrared Auger suppressed HgCdTe multilayer structures grown on GaAs substrates designed for high operating temperature condition: 200-300 K exhibiting, detectivity -10¹¹ cmHz^1/2/W, time response within a –120 ps range at 230 K. Abnormal responsivity within the range of -30 A/W for electrical area 30×30 μm² under reverse bias V = 150 mV is reported. Maximum extraction coefficient of -2.3 was estimated for analysed structures.