From ykoshka at ece.msstate.edu Thu Jan 8 10:06:16 2009 From: ykoshka at ece.msstate.edu (Yaroslav Koshka) Date: Thu Jan 8 10:06:19 2009 Subject: [ece4243] HW In-Reply-To: <10479117.458771231430486516.JavaMail.root@zimbra.ece.msstate.edu> Message-ID: <22104778.458791231430776777.JavaMail.root@zimbra.ece.msstate.edu> Ladies and Gentlemen, My computer is still not working, so our communication is problematic. I would appreciate if everybody respond to my e-mail confirming receiving it. The next HW assignment is updated for tomorrow (Friday) in the Syllabus file online (MS Excel file). It is a study assignment for a new material (no exercises yet). The main points of emphasis are repeated below for your convenience. Have a good practice. ------------------------ For Jan 9 Know the meaning of the following terms: 1) Band gap and its relation to the wavelength (color) of light emitted or absorbed 2) Meaning of ?doping?. Role of doping in semiconductors 3) unit cell of a lattice 4) Miller indices. Meaning of (hkl) and {hkl} notations. From ykoshka at ece.msstate.edu Sun Jan 11 16:50:09 2009 From: ykoshka at ece.msstate.edu (Yaroslav Koshka) Date: Sun Jan 11 16:50:44 2009 Subject: [ece4243] RE: HW N1 In-Reply-To: References: Message-ID: <000801c9743e$f5c03aa0$e140afe0$@msstate.edu> Matt, This is a useful question. I include the rest of the class to this answer. The number of atoms per unit cell depends on the type of the lattice that the material has (i.e., the type of unit cell). Si is a simple cubic lattice, the cubic unit cell has 8 "corners" of cube and each corner is shared by 8 neighboring cells. More complex lattices may have it differently. This would be a subject of more extensive Crystallography (we only touch crystallography here as a flavor). When you start working with a new material, you accumulate facts like that. You can always try to find this info on the interned (e.g., type of unit cell of GaAs, or SiC, or Si, etc). Than you can do calculations as in the solutions to Prob.1.12. Does it help? -------------------------------------------- Yaroslav Koshka, PhD Associate Professor Emerging Materials Research Laboratory Dept of Electrical & Computer Engineering Mississippi State University PO Box 9571, 216 Simrall Hall, 406 Hardy Road Mississippi State, MS 39762 PHONE: (662)325-2411 FAX: (662)325-9478 YKoshka@ECE.MsState.Edu -------------------------------------------- -----Original Message----- From: Matt Gallups [mailto:mcg118@msstate.edu] Sent: Sunday, January 11, 2009 4:27 PM To: YKoshka@ece.msstate.edu Subject: HW N1 Hello Dr. Koshka, I was going through the homework you gave for physical electronics and I have a question. I tried working some of the problems on my own and had some trouble. So, I looked at the solution you gave us and all of the solutions seem to use the number of atoms per cell. I was wondering how do you find the number of atoms/cell or is this just something we have to look up and memorize? Hope you are having a wonderful day, Matt Gallups From ykoshka at ece.msstate.edu Sun Jan 11 16:51:08 2009 From: ykoshka at ece.msstate.edu (Yaroslav Koshka) Date: Sun Jan 11 16:51:32 2009 Subject: [ece4243] RE: HW N1 In-Reply-To: References: Message-ID: <000901c9743f$18570e90$49052bb0$@msstate.edu> Matt, This is a useful question. I include the rest of the class to this answer. The number of atoms per unit cell depends on the type of the lattice that the material has (i.e., the type of unit cell). Si is a simple cubic lattice, the cubic unit cell has 8 "corners" of cube and each corner is shared by 8 neighboring cells. More complex lattices may have it differently. This would be a subject of more extensive Crystallography (we only touch crystallography here as a flavor). When you start working with a new material, you accumulate facts like that. You can always try to find this info on the interned (e.g., type of unit cell of GaAs, or SiC, or Si, etc). Than you can do calculations as in the solutions to Prob.1.12. Does it help? -------------------------------------------- Yaroslav Koshka, PhD Associate Professor Emerging Materials Research Laboratory Dept of Electrical & Computer Engineering Mississippi State University PO Box 9571, 216 Simrall Hall, 406 Hardy Road Mississippi State, MS 39762 PHONE: (662)325-2411 FAX: (662)325-9478 YKoshka@ECE.MsState.Edu -------------------------------------------- -----Original Message----- From: Matt Gallups [mailto:mcg118@msstate.edu] Sent: Sunday, January 11, 2009 4:27 PM To: YKoshka@ece.msstate.edu Subject: HW N1 Hello Dr. Koshka, I was going through the homework you gave for physical electronics and I have a question. I tried working some of the problems on my own and had some trouble. So, I looked at the solution you gave us and all of the solutions seem to use the number of atoms per cell. I was wondering how do you find the number of atoms/cell or is this just something we have to look up and memorize? Hope you are having a wonderful day, Matt Gallups