The oxygen dimer in Si: Its relationship to the light-induced degradation of Si solar cells?

Abstract

It is widely believed that the light induced degradation of crystalline silicon solar cells is due to the formation of a B s O 2i recombination center created by the optically excited migration of the oxygen dimer ͑charge-state-driven motion͒. In this letter the concentration dependence of the neutral state of O 2i on ͓O i ͔ in p-and n-type Cz-Si has been determined using infrared absorption. A systematic search for the absorption signature of the dimer in the doubly positively charged state has been unsuccessful. These data strongly suggest that charge-state-driven motion ͑Bourgoin-Corbett mechanism͒ of the oxygen dimer cannot occur in typical solar silicon and hence bring into question the accepted degradation mechanism.

Direct monitoring of minority carrier density during light induced degradation in Czochralski silicon by photoluminescence imaging

“…3 Recent work published in 2011 4 stated, however, that this type of motion of an oxygen dimer is a highly unlikely mechanism in solar grade silicon. Accordingly, this hypothesis disputed the role of the excess carriers in the model.…”

G-centers in irradiated silicon revisited: A screened hybrid density functional theory approach

“…Silicon (Si) is an important material for numerous devices (e.g., microelectronic and photovoltaic), though its electronic properties and defect processes are significantly affected by the presence of impurities, [1][2][3][4][5][6] where carbon (C) is a common impurity in the mono-crystalline Si lattice and is incorporated inadvertently during the Czochralski growth process. 7 C is isovalent with Si and occupies electrically neutral substitutional sites (C s ).…”

IR studies of the oxygen and carbon precipitation processes in electron irradiated tin-doped silicon

“…We assume that a number of V survives annihilation according to reaction (4) and these vacancies participate in reactions (5) and (6). Reaction kinetics theory impose [132] that due to the provision of these additional V the equilibrium of the latter reactions shifts in the forward direction.…”

“…The miniaturization of devices constitutes defect processes very important as their detailed understanding may influence material and/or device properties [5][6][7][8]. In particular during the manufacturing of devices thermal annealing, irradiation and doping are among the most usual technological processes of Si, however, they unavoidably introduce defects.…”