The parameters of crystalline semiconductor such as types of semiconductor, uniformity of impurity concentration of doped wafer, majority charge carrier concentration, sheet resistivity of doped wafer surface play an important role in solar cell fabrication process during emitter diffusion, that is the most critical step. In this paper, we have used a low cost in house made hot probe measurement setup. A hot plate was used to heat up the wafer up to 100°C. Two k-type thermocouples were placed simultaneously in contact with the hot and cold surface of the wafer to measure the temperature in situ for both hot and cold probe. We have used two copper probes with a voltmeter connected to measure the potential difference (thermoelectric voltage) between two probes for various temperatures up to 100°C with an interval of 10°C. We have taken measurement for commercial silicon wafer (thickness 200 µm) and one side polished 4 inch diameter Si wafer (thickness 660 µm) to determine the wafer type (n-type or p-type). We also calculated thermopower or Seebeck coefficient from the voltage vs. time curve, that is constant for particular substrate. As a process monitoring tool for solar cell fabrication process, after n-type diffusion using POCl3 on p-type silicon wafer of thickness 200 µm, we have done wafer mapping that gives us the information of doping uniformity over the whole surface of wafer both front and back side

This study presented a technique to deposit high strength and highly conductive copper thin films on glass substrates at room temperature. In this work, Cu thin films with thicknesses ~500 nm have been deposited on glass substrate by thermal evaporation technique at room temperature. After deposition, these films have been annealed at 200˚C for 10 -40 minutes. The thickness and annealing effect on the structural and morphological properties were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The results showed that by increasing thickness the copper films crystallinity in (111) direction had been increased. Also by varying the annealing time the significant changes were observed in the films crystallinity and surface morphology.

The parameters of crystalline semiconductor such as types of semiconductor, uniformity of impurity concentration of doped wafer, majority charge carrier concentration, sheet resistivity of doped wafer surface play an important role in solar cell fabrication process during emitter diffusion, that is the most critical step. In this paper, we have used a low cost in house made hot probe measurement setup. A hot plate was used to heat up the wafer up to 100°C. Two k-type thermocouples were placed simultaneously in contact with the hot and cold surface of the wafer to measure the temperature in situ for both hot and cold probe. We have used two copper probes with a voltmeter connected to measure the potential difference (thermoelectric voltage) between two probes for various temperatures up to 100°C with an interval of 10°C. We have taken measurement for commercial silicon wafer (thickness 200 µm) and one side polished 4 inch diameter Si wafer (thickness 660 µm) to determine the wafer type (n-type or p-type). We also calculated thermopower or Seebeck coefficient from the voltage vs. time curve, that is constant for particular substrate. As a process monitoring tool for solar cell fabrication process, after n-type diffusion using POCl3 on p-type silicon wafer of thickness 200 µm, we have done wafer mapping that gives us the information of doping uniformity over the whole surface of wafer both front and back side

Although large electronic systems can be constructed almost entirely with digital techniques, many systems still have analog components and current mirror is the core structure for almost all analog and mixed mode circuits. It determines the performance of analog structures, which largely depends on their characteristics. In this paper, we have analyzed a basic type as well as a cascade type of current mirror using enhancement type MOSFET and study different parameters like minimum output voltage, equivalent resistance and output sink current characteristics etc.

A Pico-ammeter has versatile application in the measurement of low current of nuclear detector, biological cell or tissues and to know the character of new electronic devices. But noise can be generated due to some internal and external sources such as, poor design, placement of ammeter, dust, humidity, bending of connecting wires and even the selection of electronic devices, thus the measurement goes tricky. Several design techniques, guarding, shielding, and an unconventional wiring technique can help to measure low current accurately by reducing noise. This paper describes this low current measurement problems in detail and their corresponding solutions. It also shows the comparison of different low current measurement systems (LCMS). Feedback type ammeters are more preferable than shunt ammeter and current conveyor technique. In operational amplifier selection, CMOS type op-amp is better than BJT and FET.