Modelling of Current Transport Mechanisms in GaSb-Rich Type-II Superlattice Infrared Photodiodes
Vishnu Gopal,
Raghvendra Sahai Saxena
Issue:
Volume 11, Issue 4, August 2023
Pages:
82-88
Received:
3 July 2023
Accepted:
5 August 2023
Published:
15 August 2023
Abstract: In this paper we propose an alternative approach to model the performance limiting current leakage mechanism in GaSb-rich type II superlattice diodes than reported earlier. The reported conclusions are based on the analysis of the current – voltage (I – V) and dynamic resistance – voltage (Rd – V) characteristics of these diodes. None of the carrier transport parameters evaluated from independent measurements on similar samples are used in the present analysis as some of the material parameters like carrier concentrations and mobilities are evaluated by Hall measurements along the planes parallel to the deposited layers constituting the superlattice, whereas the transport of carriers in practical superlattice diodes takes place in the vertical direction. Instead, we have used a method which extracts the desired parameters from the measured I – V itself. Our analysis has shown that the GaSb-rich superlattice diode’s performance limiting leakage current mechanism is the contribution from surface leakage currents, which have been modelled as shunt current that is of ohmic nature in low reverse bias region near zero-bias. The same leakage current however grows in its own proportion leading to an exponential increase of the leakage current in the higher reverse bias region. The reverse bias region corresponding to the exponential increase of the leakage current exhibits consequent degradation in the dynamic resistance of the diode leaving behind a peak in the dynamic resistance characteristic. The reverse bias voltage corresponding to the peak dynamic resistance is the limiting bias voltage for the ohmic behaviour of the shunt current.
Abstract: In this paper we propose an alternative approach to model the performance limiting current leakage mechanism in GaSb-rich type II superlattice diodes than reported earlier. The reported conclusions are based on the analysis of the current – voltage (I – V) and dynamic resistance – voltage (Rd – V) characteristics of these diodes. None of the carrie...
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Performance Evaluation of a Modified ECG De-noising Technique Using Wavelet Decomposition and Threshold Method
Sucharita Mitra Sarkar,
Priyanka Samanta
Issue:
Volume 11, Issue 4, August 2023
Pages:
89-98
Received:
2 July 2023
Accepted:
9 August 2023
Published:
22 August 2023
Abstract: According to recent survey due to drastically changing weather and unhealthy lifestyle, irrespective of age people are suffer from different health issues, among them heart related diseases are very common. So to prevent some emergency health hazards due to such kind of diseases distant and continuous health monitoring is very useful, but due to lack of expert intervention both processes are very sensitive to noise. So our aim is to get a noise free medical data through above said processes to treat a patient properly. In this work experimental signal data is chosen from a 12 lead noisy ECG database which is formed using a MATLAB coded program by taking noisy and clear data from MIT-BIH noise stress test database and CSE clear ECG database respectively. Generated noisy ECG signals are decomposed using wavelet decomposition. Distorted coefficients generated during the process are recovered using threshold technique and the de-noised signal is achieved using changed coefficients. After de-noising process amplitude and duration of different segments and intervals of de-noised ECG signals for several SNR values and also for clear ECG signals are obtained by running an ECG feature extraction program developed in MATLAB. Compare both parameters to study the performance of the whole de-noising procedure, Again sensitivity, predictivity and detection accuracy are checked for each de-noised data for different SNR values and represent them graphically to detect the accuracy of the process.
Abstract: According to recent survey due to drastically changing weather and unhealthy lifestyle, irrespective of age people are suffer from different health issues, among them heart related diseases are very common. So to prevent some emergency health hazards due to such kind of diseases distant and continuous health monitoring is very useful, but due to la...
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