{"id":{"repo_id":"njit","oai_identifier":"oai:digitalcommons.njit.edu:theses-1186"},"canonical_url":"https://search.dev.ndltd.org/etd/njit/oai:digitalcommons.njit.edu:theses-1186","repository":{"repo_id":"njit","name":"NJIT","base_url":"https://digitalcommons.njit.edu/do/oai/"},"display":{"title":"Effect of temperature on tunneling and quantum efficiency in cigs solar cells","abstract":"Utilizing the two-band approximation and Wentzel-Kramers-B ri l l oui n (WKB) approximation, by including the temperature-dependent effective masses and nonparabolicity effects, an investigation of the temperature dependent band-to-band tunneling process is discussed. In comparison with the parabolic approximation and non- parabolic approximation, the tunneling probability is strongly dependent on the non-parabolicity factor. The temperature dependence of the energy band gap, electron effective mass and light hole effective mass is investigated. The tunneling current density function is derived by a series representation of the incomplete gamma function with non-parabolic effect and its variation at low temperature is also investigated. When the Fermi level of holes is in excess of that of electrons, i.e., E_{Fp}>>E_{Fn}, the current density function can be successfully simplified as the Fowler-Nordheim formulation. The quantum efficiency model, for CIGS solar cells, is discussed. Device modeling and simulation studies of a Cu(In_{1-x},Gax)Se_2 (CIGS) thin film solar cell are carried out. A variety of graded band-gap structures, including space charge region (SCR) grading, back surface region grading, and double grading of the CIGS absorber layer are considered. A position-dependent absorption coefficient [alpha](x, hv) is obtained by a differential equation for the photon flux [phi](x, hv). The quantum efficiency can be calculated by IQE=([phi]_1-[phi]_2)/[phi]_3. The temperature dependence of the quantum efficiency is also investigated in this thesis.","abstract_html":"Utilizing the two-band approximation and Wentzel-Kramers-B ri l l oui n (WKB) approximation, by including the temperature-dependent effective masses and nonparabolicity effects, an investigation of the temperature dependent band-to-band tunneling process is discussed. In comparison with the parabolic approximation and non- parabolic approximation, the tunneling probability is strongly dependent on the non-parabolicity factor. The temperature dependence of the energy band gap, electron effective mass and light hole effective mass is investigated. The tunneling current density function is derived by a series representation of the incomplete gamma function with non-parabolic effect and its variation at low temperature is also investigated. When the Fermi level of holes is in excess of that of electrons, i.e., E_{Fp}>>E_{Fn}, the current density function can be successfully simplified as the Fowler-Nordheim formulation. The quantum efficiency model, for CIGS solar cells, is discussed. Device modeling and simulation studies of a Cu(In_{1-x},Gax)Se_2 (CIGS) thin film solar cell are carried out. A variety of graded band-gap structures, including space charge region (SCR) grading, back surface region grading, and double grading of the CIGS absorber layer are considered. A position-dependent absorption coefficient [alpha](x, hv) is obtained by a differential equation for the photon flux [phi](x, hv). The quantum efficiency can be calculated by IQE=([phi]_1-[phi]_2)/[phi]_3. The temperature dependence of the quantum efficiency is also investigated in this thesis.","abstract_has_math":false,"creators":["Liu, Sizhan"],"institution":null,"degree_name":"Master of Science in Materials Science and Engineering - (M.S.)","degree_level":null,"degree_discipline":"Committee for the Interdisciplinary Program in Materials Science and Engineering","degree_department":null,"school":null,"contributors":["N. M. Ravindra","Halina Opyrchal","Tao Zhou"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-01-31T08:00:00Z","date_published":"2014-01-31T08:00:00Z","updated_at":"2026-07-24T03:22:26Z","subjects":["Band-to-band tunneling","Quantum efficiency","Materials Science and Engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.njit.edu/theses/187","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["N. M. 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In comparison with the parabolic approximation and non- parabolic approximation, the tunneling probability is strongly dependent on the non-parabolicity factor. The temperature dependence of the energy band gap, electron effective mass and light hole effective mass is investigated. The tunneling current density function is derived by a series representation of the incomplete gamma function with non-parabolic effect and its variation at low temperature is also investigated. When the Fermi level of holes is in excess of that of electrons, i.e., E_{Fp}>>E_{Fn}, the current density function can be successfully simplified as the Fowler-Nordheim formulation. The quantum efficiency model, for CIGS solar cells, is discussed. Device modeling and simulation studies of a Cu(In_{1-x},Gax)Se_2 (CIGS) thin film solar cell are carried out. A variety of graded band-gap structures, including space charge region (SCR) grading, back surface region grading, and double grading of the CIGS absorber layer are considered. A position-dependent absorption coefficient [alpha](x, hv) is obtained by a differential equation for the photon flux [phi](x, hv). The quantum efficiency can be calculated by IQE=([phi]_1-[phi]_2)/[phi]_3. The temperature dependence of the quantum efficiency is also investigated in this thesis."]},{"key":"dc:title","label":"Title","values":["Effect of temperature on tunneling and quantum efficiency in cigs solar cells"]}]}],"canonical_facts":{"dc:contributor":["N. M. Ravindra","Halina Opyrchal","Tao Zhou"],"dc:creator":["Liu, Sizhan"],"dc:description.abstract":["Utilizing the two-band approximation and Wentzel-Kramers-B ri l l oui n (WKB) approximation, by including the temperature-dependent effective masses and nonparabolicity effects, an investigation of the temperature dependent band-to-band tunneling process is discussed. In comparison with the parabolic approximation and non- parabolic approximation, the tunneling probability is strongly dependent on the non-parabolicity factor. The temperature dependence of the energy band gap, electron effective mass and light hole effective mass is investigated. The tunneling current density function is derived by a series representation of the incomplete gamma function with non-parabolic effect and its variation at low temperature is also investigated. When the Fermi level of holes is in excess of that of electrons, i.e., E_{Fp}>>E_{Fn}, the current density function can be successfully simplified as the Fowler-Nordheim formulation. The quantum efficiency model, for CIGS solar cells, is discussed. Device modeling and simulation studies of a Cu(In_{1-x},Gax)Se_2 (CIGS) thin film solar cell are carried out. A variety of graded band-gap structures, including space charge region (SCR) grading, back surface region grading, and double grading of the CIGS absorber layer are considered. A position-dependent absorption coefficient [alpha](x, hv) is obtained by a differential equation for the photon flux [phi](x, hv). The quantum efficiency can be calculated by IQE=([phi]_1-[phi]_2)/[phi]_3. The temperature dependence of the quantum efficiency is also investigated in this thesis."],"dc:identifier":["https://digitalcommons.njit.edu/theses/187"],"dc:subject":["Band-to-band tunneling","Quantum efficiency","Materials Science and Engineering"],"dc:title":["Effect of temperature on tunneling and quantum efficiency in cigs solar cells"],"dc:type":["Thesis"],"thesis:degree_discipline":["Committee for the Interdisciplinary Program in Materials Science and Engineering"],"thesis:degree_name":["Master of Science in Materials Science and Engineering - (M.S.)"]},"updated_at":"2026-07-24T03:22:26Z"}