Electrical and optical characteristics of InP Interband Nanowire Infrared Photodetectors

3 Description of cover page picture: Test sample of InP nanowire 4 Preface First of all we would like to show our deepest gratitude to our supervisor and mentor Dr. Lars Landin and we are also grateful to him for his precious time and cordial help in a number of ways. We are extremely glad that he has made it possible for us to work in this new photodetector technology project based on nanowires. We also owe our deepest gratitude to Professor Håkan Pettersson who proposed the project and invited us to carry out the project work in MPE-Lab at Halmstad University, Sweden. It was a real pleasure to work with those who made this thesis possible and to learn vast knowledge from such experienced persons. Finally, we would like to thank our parents and family members for their understanding and support to us throughout our lives. Without help of them, we would face many difficulties while doing this project. Abstract We have investigated two devices for detection of radiation, typically in the infrared range, Photons are absorbed in an active region of semiconductor devices such that the absorption induces inter band electronic transitions and generate photo-excited charge carriers. A photocurrent is generated between the conducting contacts through the active region of the devices. We worked on infrared photodectors based on nanowires. This type of photodectors can be used for optical communication and to detect atmospheric pollution by absorption of the polluting molecules in the infrared region (0.7µm-1µm). In this project we have used Fourier transform infrared spectroscopy to study and compared the photoresponse of two different types of interband nanowire infrared photodetectors 8samples 6080 and 6074). Fourier Transform infrared (FTIR) spectroscopy is a measurement technique that allows one to record infrared spectra in all wavelengths at then same time. The basic task was to compare and analyse the electrical and optical characteristics of these two detectors at different temperatures (78K-300K) corresponding to the wavelength.