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"Semiconductor optics provides an introduction to and an overview of semiconductor optics from the IR through the visible to the UV, including linear and nonlinear optical properties, dynamics, magneto and electrooptics, high-excitation effects and laser processes, some applications, experimental techniques and group theory.The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered extend from physics to materials science and optoelectronics. Significantly updated chapters add coverage of current topics such as electron hole plasma, Bose condensation of excitons and meta materials. Over 120 problems, chapter introductions and a detailed index make it the key textbook."

"ABSTRACTThe role of excitons in semiconducting materials carries potential applications. Excitonic signals usually do not appear clearly in optical absorption spectra of semiconductor systems with narrow gap, such as Gallium Arsenide, which makes experimental analyses on excitons in such systems become very challenging. On the iii iv theoretical side, calculation of optical spectra based purely on Density Functional Theory DFT without taking electron hole interactions into account does not lead to the appearance of any excitonic signal. Meanwhile, existing DFT based algorithms that include a full vertex correction through Bethe Salpeter equation may reveal an excitonic signal, but the algorithm has not provided a way to analyze the excitonic signal further. Motivated to provide a way to isolate the excitonic effect in the optical response theoretically, we develop a method of calculation for the optical conductivity of a narrow band gap semiconductor GaAs within the k.p 8 band model, that includes electron hole interactions through first order electron hole vertex correction. The k.p model is chosen because it provides a description of 8 energy bands 2 conduction and 6 valence bands in which the role of spin orbit coupling is also taken into account. We expect that this first order vertex correction reveals how the optical spectral weight redistributes as a function of temperature.

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ABSTRAKPeran eksiton pada material semikonduktor membawa banyak potensi aplikasi. Sinyal eksiton tidak terlalu jelas kemunculannya pada spektrum absorbsi optis semikonduktor bercelah sempit, seperti Gallium Arsenite, sehingga analisis keberadaan eksiton secara eksperimen menjadi cukup menantang. Dari segi teori, perhitungan dengan metode Density Functional Theory DFT yang tidak melibatkan interaksi electron-hole belum dapat menunjukan keberadaan eksiton. Sedangkan untuk perhitungan DFT yang mengikutsertakan koreksi vertex secara lengkap dengan metode Bethe-Salpeter equation BSE dapat memunculkan sinyal eksiton, namun algoritma yang ada belum dapat memberi cara untuk menganalisis eksiton lebih jauh. Dengan motifasi tersebut, kami mengembangkan metode perhitungan konduktifitas optis semikonduktor bercelah sempit material Gallium Arsenite dengan menerapkan model k.p 8 pita, dengan mengikutsertakan interaksi electronhole melalui koreksi verteks orde pertama. Metode k.p di pilih karena metode ini dapat menjelaskan 8 pita 2 pita konduksi dan 6 pita valensi dan turut melibatkan faktor spin orbit coupling."

"This monograph solely presents the Fowler-Nordheim field emission (FNFE) from semiconductors and their nanostructures. The materials considered are quantum confined non-linear optical, III-V, II-VI, Ge, Te, carbon nanotubes, PtSb2, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V, Bi2Te3, III-V, II-VI, IV-VI and HgTe/CdTe superlattices with graded interfaces and effective mass superlattices under magnetic quantization and quantum wires of the aforementioned superlattices. The FNFE in opto-electronic materials and their quantum confined counterparts is studied in the presence of light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The importance of band gap measurements in opto-electronic materials in the presence of external fields is discussed from this perspective. This monograph contains 200 open research problems. "

"ABSTRAKKebutuhan akan semikonduktor pada perangkat listrik yang memiliki ketahanan yang baik dikondisi lingkungan ekstrim membuat silikon karbida SiC menjadi pilihan yang sangat menjanjikan. SiC dapat diaplikasikan untuk daya tinggi, frekuensi tinggi, dan suhu tinggi. SiC memiliki sifat semikonduktor intrinsik dengan banyak kelebihan dibandingkan semikonduktor silikon. SiC merupakan bahan dengan konduktivitas panas yang tinggi serta memiliki sifat yang stabil terhadap mekanik dan kimia serta tahan terhadap radiasi. Dalam penelitian ini telah dilakukan sintesis serat SiC dengan prekursor polimer polycarbosilane PCS menggunakan metode elektrospinning dengan pelarut N,N-dimetilformamida DMF dan toluena. Metode elektrospinning ini sangat baik untuk membuat serat dengan diameter yang terkontrol dan kurang dari 10 m. Tegangan pada proses elektrospinning divariasikan untuk mengetahui pengaruhnya terhadap diameter serat yang dihasilkan serta dilakukan pula variasi suhu pada proses pirolisis untuk mengetahui proses degradasi kimia pada saat pembentukan serat SiC dari serat PCS. Serat SiC yang diperoleh kemudian dikarakterisasi dan diuji sifat kelistrikannya. Hasil karakterisasi menunjukkan serat SiC telah berhasil disintesis dengan metode elektrospinning yang kemudian melalui tahapan proses curing dan pirolisis. Morfologi serat yang dihasilkan yaitu berbentuk pipa dan memiliki keseragaman yang baik. Semakin meningkatnya tegangan selama proses elektrospinning serta dengan bertambahnya suhu pirolisis memberikan diameter serat yang lebih kecil dengan diamater rerata sebesar 4,3 m . Sifat kelistrikan serat SiC hasil sintesis memiliki band gap 2,56 eV dan area nilai konduktivitas listriknya adalah dari 8 10-6 hingga 7 10-6 S/cm.

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ABSTRACTThe need for semiconductors in electrical devices that have good resistance in extreme environment conditions make silicon carbide SiC very promising choice. SiC can be applied for high power, high frequency, and high temperature. SiC has intrinsic semiconductor properties with many advantages over silicon semiconductors. SiC is a material with high thermal conductivity and has properties that are mechanically and chemically stable and resistant to radiation. In this research, SiC fiber synthesis with polycarbosilane polymer precursor PCS has been done using electrospinning method with N, N dimethylformamide DMF and toluenae solvent. This electrospinning method is very good for making fibers with controlled diameters and less than 10 m. The voltage on the electrospinning process is varied to determine the effect on the fiber diameter produced and also the temperature variation in the pyrolysis process to determine the chemical degradation process at the time of fiber SiC formation of PCS fibers. SiC fibers obtained are then characterized and tested for their electrical properties. The characterization results show that SiC fibers have been successfully synthesized by electrospinning method which then through the curing process and pyrolysis stage. The resulting fiber morphology is pipe shaped and has good uniformity. The increasing stresses during the electrospinning process and with increasing pyrolysis temperature give the fiber diameter smaller with the average diameter of 4.3 m. The synthetic nature of SiC fibers has a band gap of 2.56 eV and the electrical conductivity value is from 8 10 6 to 7 10 6 S cm."

"Material low band gap baru tipe-p Poly 2,2 39;- 2,5-bis 2-octyldodecyl -3,6-dioxo-2,3,5,6- tetrahydropyrrolo[3,4-c] pyrrole-1,4-diyl dithieno[3,2-b]thiophene-5,5 39;- diyl-alt-thiophen-2,5-diyl telah menarik banyak perhatian untuk aplikasi sebagai material fotoaktif pada divais elektronik seperti pada sel surya dan fotodetektor. Modifikasi morfologi pada lapisan fotoaktif menjadi tantangan karena panjang difusi exciton pada semikonduktor organic terbatas hanya 10-20 nm. Oleh karena itu, bentuk dan struktur material semikonduktor organic menggunakan template AAO untuk membuat berbagai macam struktur nano seperti nanotube,nanorod, dan struktur nano yang lain semakin menarik perhatian peneliti.Pada penelitian ini, sintesis dan karakterisasi sifat optik dan struktur material PDPPBTT nanotube telah dilakukan. Struktur PDPPBTT nanotube telah dibuat dengan menggunakan AAO template yang diinfiltrasi dengan metode sentrifugasi. Larutan polimer dibuat dengan dua konsentrasi, yaitu 5 mg/mL dan 10 mg/mL dan dilakukan variasi kecepatan putar centrifuge yaitu 3000, 3500 dan 4000 rpm. Karakterisasi sifat optik dilakukan dengan UV-Vis spektrofotometer dan Photoluminescence, karakterisasi morfologi dengan FESEM dan analisis struktur dengan Raman.Berdasarkan hasil UV-Vis, intensitas serapan PDPPBTT 5 mg/mL pada kecepatan putar 3000 rpm menunjukkan hasil yang paling tinggi dibandingkan dengan kecepatan putar yang lain. Hal ini juga didukung dengan hasil pengujian morfologi yang memperlihatkan struktur nanotube pada 3000 rpm lebih panjang dan rapat. Selain pengaruh kecepatan putar, penelitian ini juga membahas tentang pengaruh konsentrasi larutan. Larutan dengan konsentrasi 10 mg/mL terlihat lebih baik dibandingkan dengan konsentrasi 5 mg/mL, hal tersebut dapat dilihat dari hasil pengujian morfologinya. Konsentrasi 10 mg/ml struktur nano nya sangat rapat dan kuat sehingga membentuk rumpun clump . Hal ini berkaitan dengan transfer muatan yang terjadi pada material PDPPBTT. Dari hasil Photoluminescence, konsentrasi yang besar juga berpengaruh terhadap mekanisme intra atau intermolekul pada rantai polimer, hal itu terlihat pada hasilnya yang mengalami penurunan intensitas dan redshift. Berdasarkan penelitian ini, material PDPPBTT berpotensi kuat untuk dapat diaplikasikan dalam sebuah divais optoelektronik.

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The novel highly conductive low band gap p type materials, Poly 2,2 39 2,5 bis 2 octyldodecyl 3,6 dioxo 2,3,5,6 tetrahydropyrrolo 3,4 c pyrrole 1,4 diyl dithieno 3,2 b thiophene 5,5 39 diyl alt thiophen 2,5 diyl has attracted numerous attention for potential applications as a photoactive material of optoelectronic devices such as solar cells and photodetector. The morphological control of the photoactive layer remains a challenge due to the exciton diffusion length of organic semiconductors is limited to 10 20 nm. Therefore the patterning of organic semiconducting materials using hard templates for fabrication of nanostructures such as nanotubes, nanorods, and other novel nanostructures attracted increasing attention.In this study, synthesis and characterization of optical properties and structure of PDPPBTT nanotube have been performed. The structure of PDPPBTT nanotubes have been made using AAO templates infiltrated by centrifugation method. Polymer solution was made with two concentrations 5 mg mL and 10 mg ml. Moreover, the centrifuge rotation speed which were used varied from 3000, 3500 and 4000 rpm. The characterization of optical properties was performed with UV Vis spectrophotometers and Photoluminescence, morphological characterization with FESEM and structural analysis with Raman spectroscopy.Based on the UV Vis results, the absorbance of PDPPBTT with 5 mg mL at 3000 rpm showed the highest value compared to other rotation speed. It rsquo s also supported by the results of morphological test which showed longer length and denser distribution at 3000 rpm rotation speed. Moreover, the effect of concentration on optical property, morphology, and structure have also been studied. The solution with 10 mg mL concentration showed better result compared to 5 mg mL concentration. The morphological measurement showed that the nanostructure obtained from 10 mg ml concentration formed a dense and strong clump. This is related to the charge transfer that occurs on PDPPBTT material. Photoluminescence measurement showed that difference in concentration value affect the intra or intermolecular mechanism in the polymer chain. This could be seen from extremely decrease of intensity and redshift which is found from the result of photoluminescence measurement."

"Recently, gallium nitride (GaN) material has attracted the attention of researchers as a candidate for third generation semiconductor material for optical telecommunication applications. In this research, a 2x2 multimode interference optical power splitter (MMI) based on a waveguide and ridge structure is proposed using gallium nitride material on a silicon (GaN/Si) substrate for optical telecommunication applications. The design optimization carried out resulted in two optical power splitter designs based on rib (design A) and ridge (design D) waveguide. Based on the simulation using the eigenmode expansion method (EME) algorithm, design A has an optimal dimension of 15 m 212 m with an insertion loss of 0.085 dB, power balancing of 0.007 dB, C-band (1530 nm – 1565 nm) broadband bandwidth of 0.140 dB, and fabrication tolerances for width and length are ± 0.3 m and ± 0.5 m, respectively. Meanwhile, design D has optimal dimensions of 15 m 214 m with insertion loss of 0.036 dB, power balancing of 0.017 dB, C-band broadband bandwidth of 0.088 dB, and fabrication tolerances for width and length respectively. of ± 0.3 m and ± 0.5 m"