![]() Siebentritt, Susanne ![]() in Advanced Energy Materials (2020) Detailed reference viewed: 65 (4 UL)![]() Weiss, Thomas ![]() ![]() ![]() in Physical Review Applied (2020), 14 Detailed reference viewed: 61 (3 UL)![]() Arnou, Panagiota ![]() ![]() ![]() in RSC Advances (2020) Detailed reference viewed: 92 (10 UL)![]() Weiss, Thomas ![]() in Scientific Reports (2019), 9 The knowledge of minority carrier lifetime of a semiconductor is important for the assessment of its quality and design of electronic devices. Time-resolved photoluminescence (TRPL) measurements offer the ... [more ▼] The knowledge of minority carrier lifetime of a semiconductor is important for the assessment of its quality and design of electronic devices. Time-resolved photoluminescence (TRPL) measurements offer the possibility to extract effective lifetimes in the nanosecond range. However, it is difficult to discriminate between surface and bulk recombination and consequently the bulk properties of the semiconductor cannot be estimated reliably. Here we present an approach to constrain systematically the bulk and surface recombination parameters in semiconducting layers and reduces to finding the roots of a mathematical function. This method disentangles the bulk and surface recombination based on TRPL decay times of samples with different surface preparations. The technique is exemplarily applied to a CuInSe2 and a back-graded Cu(In,Ga)Se2 compound semiconductor, and upper and lower bounds for the recombination parameters and the mobility are obtained. Sets of calculated parameters are extracted and used as input for simulations of photoluminescence transients, yielding a good match to experimental data and validating the effectiveness of the methodology. A script for the simulation of TRPL transients is provided. [less ▲] Detailed reference viewed: 11 (0 UL)![]() Weiss, Thomas ![]() ![]() in Science and Technology of Advanced Materials (2019), 20 Detailed reference viewed: 125 (2 UL)![]() Werner, Florian ![]() ![]() ![]() in Progress in Photovoltaics (2018) Detailed reference viewed: 171 (5 UL)![]() Rey, Germain ![]() ![]() ![]() in Thin Solid Films (2016), 633 Low temperature post-deposition treatment of Cu2ZnSnSe4 with NaF and KF significantly improved the solar cell efficiency (from 6.4% to 7.8% and 7.7% on average, respectively) due to enhanced fill factor ... [more ▼] Low temperature post-deposition treatment of Cu2ZnSnSe4 with NaF and KF significantly improved the solar cell efficiency (from 6.4% to 7.8% and 7.7% on average, respectively) due to enhanced fill factor (from 0.58 to 0.61 and 0.62), open-circuit voltage (Voc) (from 314 mV to 337 mV and 325 mV) and short-circuit current density (from 35.3 mA⋅cm −2 to 38.3 mA⋅cm −2 and 38.6 mA⋅cm −2). Voc improvement was higher for solar cells with NaF treatment due to an increase in radiative efficiency at room temperature and shallower defect activation energy as determined by photoluminescence (PL) and temperature dependent admittance spectroscopy, respectively. In the case of KF treatment, red-shift of the PL, higher band tail density of state and donor activation energy deeper in the band gap were limiting further improvement of the Voc compared to NaF treatment. [less ▲] Detailed reference viewed: 191 (10 UL)![]() Weiss, Thomas ![]() ![]() ![]() in Journal of Applied Physics (2016), 120 Detailed reference viewed: 175 (10 UL)![]() Rey, Germain ![]() ![]() ![]() in Solar Energy Materials & Solar Cells (2016), 151 Detailed reference viewed: 237 (17 UL)![]() Weiss, Thomas ![]() Doctoral thesis (2015) Detailed reference viewed: 164 (16 UL)![]() Siebentritt, Susanne ![]() ![]() ![]() in Solar Energy Materials & Solar Cells (2015) Detailed reference viewed: 232 (7 UL)![]() Hala, Matej ![]() ![]() in Progress in Photovoltaics: Research and Applications (2015) We present an approach for deposition of highly conductive nominally undoped ZnO films that are suitable for the n-type window of low band gap solar cells. We demonstrate that low-voltage radio frequency ... [more ▼] We present an approach for deposition of highly conductive nominally undoped ZnO films that are suitable for the n-type window of low band gap solar cells. We demonstrate that low-voltage radio frequency (RF) biasing of growing ZnO films during their deposition by non-reactive sputtering makes them as conductive as when doped by aluminium (ρ≤1·10−3Ω cm). The films prepared with additional RF biasing possess lower free-carrier concentration and higher free-carrier mobility than Al-doped ZnO (AZO) films of the same resistivity, which results in a substantially higher transparency in the near infrared region (NIR). Furthermore, these films exhibit good ambient stability and lower high-temperature stability than the AZO films of the same thickness. We also present the characteristics of Cu(InGa)Se2, CuInSe2 and Cu2ZnSnSe4-based solar cells prepared with the transparent window bilayer formed of the isolating and conductive ZnO films and compare them to their counterparts with a standard ZnO/AZO bilayer. We show that the solar cells with nominally undoped ZnO as their transparent conductive oxide layer exhibit an improved quantum efficiency for λ > 900 nm, which leads to a higher short circuit current density JSC. This aspect is specifically beneficial in preparation of the Cu2ZnSnSe4 solar cells with band gap down to 0.85 eV; our champion device reached a JSC of nearly 39 mAcm−2, an open circuit voltage of 378 mV, and a power conversion efficiency of 8.4 %. [less ▲] Detailed reference viewed: 279 (15 UL)![]() ; Mousel, Marina ![]() ![]() in JOURNAL OF APPLIED PHYSICS (2015), 118 Detailed reference viewed: 189 (6 UL)![]() Rey, Germain ![]() ![]() ![]() in Applied Physics Letters (2014), 105 Detailed reference viewed: 230 (21 UL)![]() Weiss, Thomas ![]() ![]() ![]() in IEEE JOURNAL OF PHOTOVOLTAICS (2014), 4 Detailed reference viewed: 173 (12 UL)![]() Redinger, Alex ![]() ![]() ![]() in IEEE Journal of Photovoltaics (2014) Detailed reference viewed: 194 (8 UL)![]() Redinger, Alex ![]() ![]() ![]() Scientific Conference (2013, June) Detailed reference viewed: 153 (3 UL)![]() ![]() Weiss, Thomas ![]() ![]() ![]() Scientific Conference (2013) Detailed reference viewed: 147 (11 UL)![]() Weiss, Thomas ![]() ![]() ![]() in Applied Physics Letters (2013) Detailed reference viewed: 189 (7 UL)![]() Mousel, Marina ![]() ![]() in Advanced Energy Materials (2013), 4 Detailed reference viewed: 181 (11 UL) |
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