 Welcome to this online open course on Fundamentals of Electronic Materials and Devices. This is a 20-hour course that is spread over approximately 8 weeks. We are currently in the digital age. We all have a variety of devices like desktops, laptops, tablets, smartphones and even smart watches. We are able to connect to the internet and to each other through all of these devices and we can also share data across all of them. This is called compute continuum. This digital revolution has been made possible because of the invention of the integrated circuit and the material at the heart of the integrated circuit or IC is silicon. So earlier we used to talk about the stone age then we had the bronze age and iron age and now we can rightly say that we are in the age of silicon. Silicon is a material that is widely used in the electronics industry. One reason of course is that it is widely available. It is the second most abundant element on earth after oxygen and it is usually present in the form of its oxide, silicon dioxide. But more than that silicon has a unique electronic property. Silicon is a semiconductor that is it lies between metals which are good conductors and insulators like quartz which are bad conductors. Compared to metals silicon has a conductivity which increases with temperature while metals conductivity usually decrease with temperature. More importantly the conductivity of silicon can be changed by adding minute amounts usually parts per million or parts per billion of some other material. This process is called doping and doping makes all of the electronic devices that we see possible. In this online course we will first look at some of the fundamental properties of semiconductors. I will use silicon for many of the examples but many of the properties of silicon are also shared by other semiconductors both elemental semiconductors like germanium and compound semiconductors like gallium arsenide. We will also see how doping will modify the electronic properties of the semiconductors. We will spend approximately 8 lectures looking at these fundamental properties and then use this to look at electronics devices for the rest of the course. We will first start with simple metal semiconductor junctions and then we will move on to diodes which are formed by joining 2 semiconductors and then finally go on to the transistor. Transistors are formed by joining 3 semiconductors to each other. We will use the fundamental properties that we studied in the first part of the course to understand how all of these devices function. We will also look at optoelectronic devices which are a class of devices that combine both optical properties and electronic properties. Examples include light emitting diodes, lasers, photovoltaics and of course most famously solar cells. Silicon is used in some of these devices but silicon is not the only material that is used for optoelectronic devices because silicon is an indirect band gap semiconductor. This means that silicon does not emit light as efficiently as some of the other materials. So we will also look at some of the other semiconductors that are especially used for lighting applications like LEDs and lasers. So the video lectures in this course will also be supplemented with PDF course notes which will be available for each lecture and which will be uploaded as part of the course. So this will help the student follow the videos better and also help in improving and understanding of the course. We will also have weekly evaluation in the form of assignments. Usually these will be multiple choice questions true or false or fill in the blanks that will again help in understanding or explaining the various concepts that are covered in the lecture. This course is especially designed for the third and final year undergraduate students with a variety of background and the main aim of this course is to provide a fundamental understanding of semiconductor materials and devices. Thank you.