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QUIZ in .NET Draw Code 128 Code Set A in .NET QUIZ

QUIZ using .net torender code 128 barcode in asp.net web,windows application QR Code Spevcification 7 / c (mA) collector base emitter 15 ikn 10 IB = 0.3 mA IB = 0.2 mA loo ka V, = 11V IB = 0.1 mA v, = it v i i Ii i i i I " 10 15. vCE(v). Question 2 The fol .net framework Code 128B lowing is a band diagram within an n-p-n bipolar junction transistor (BJT) at equilibrium. Sketch in the Fermi level as a function of position.

Qualitative accuracy is sufficient.. energy, E position, x p-type n-type n-type Question 3 Would d Code 128 Code Set C for .NET ecreasing the base width of a BJT increase, decrease, or leave unchanged the following, assuming that the device remained unchanged otherwise (Circle your choice for each.) a) the emitter injection efficency y b) the base transport factor B c) the (common-emitter) gain /3 d) the magnitude of the Early voltage VA1 increase I unchanged I decrease increase I unchanged I decrease increase I unchanged / decrease increase I unchanged I decrease.

Bipolar Junction T ransistors Question 4 Sketch the cross section of an n-p-n BJT and point out the dominant current components on it showing the correct directions of the various current vectors. If we increase the base doping, qualitatively explain how the various components change..

Question 5 Would d Code 128 Code Set C for .NET ecreasing the base doping of the BJT increase, decrease, or leave essentially unchanged (circle the correct answers): (a) emitter injection efficiency 7 (b) base transport factor B (c) magnitude of the Early voltage VA1 increase I increase increase decrease I unchanged. I decrease / unchanged I decrease I unchanged 8 . Optoelectronic Devices OBJECTIVES 1. Unde Code-128 for .NET rstand solar cells 2 .

Study photodetectors such as APDs 3. Study incoherent light sources (LEDs) and coherent light sources (lasers). So far we have pri marily concentrated on electronic devices. There is also a wide variety of very interesting and useful device functions involving the interaction of photons with semiconductors. These devices provide the optical sources and detectors that allow broadband telecommunications and data transmission over optical fibers.

This important area of device applications is called optoelectronics. In this chapter we will discuss devices that detect photons and those that emit photons. Devices that convert optical energy into electrical energy include photodiodes and solar cells.

Emitters of photons include incoherent sources such as light-emitting diodes (LEDs) and coherent sources in the form of lasers.. 8.1 PHOTODIODES In Section 4.3.4 w e saw that bulk semiconductor samples can be used as photoconductors by providing a change in conductivity proportional to an optical generation rate.

Often, junction devices can be used to improve the speed of response and sensitivity of detectors of optical or high-energy radiation. Two-terminal devices designed to respond to photon absorption are called photodiodes. Some photodiodes have extremely high sensitivity and response speed.

Since modern electronics often involves optical as well as electrical signals, photodiodes serve important functions as electronic devices. In this section, we shall investigate the response of p-n junctions to optical generation of EHPs and discuss a few typical photodiode detector structures. We shall also consider the very important use of junctions as solar cells, which convert absorbed optical energy into useful electrical power.

. Optoelectronic Devices 8.1.1 Current and Voltage in an Illuminated Junction In 5 we identifie d the current due to drift of minority carriers across a junction as a generation current. In particular, carriers generated within the depletion region W are separated by the junction field, electrons being collected in the n region and holes in the p region. Also, minority carriers generated thermally within a diffusion length of each side of the junction diffuse to the depletion region and are swept to the other side by the electric field.

If the junction is uniformly illuminated by photons with hv > Eg, an added generation rate gop (EHP/cm3-s) participates in this current (Fig. 8-1).The number of holes created per second within a diffusion length of the transition region on the n side is ALpgop.

Similarly A L gop electrons are generated per second within Ln oixp() and AWgop carriers are generated within W.The resulting current due to collection of these optically generated carriers by the junction is / op = qAgop(Lp + Ln + W) (8-1). If we call the the visual .net code-128c rmally generated current described in Eq. (5-37b) /lh, we can add the optical generation of Eq.

(8-1) to find the total reverse current with illumination. Since this current is directed from n to p, the diode equation [Eq. (5-36)] becomes 1)-/.

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