Free electron gas primary thermometer: The bipolar junction transistor

Mimila-Arroyo, J.

doi:10.1063/1.4829741

Cited by 5 publications

(2 citation statements)

References 18 publications

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“…The minority carriers can reach the surfaces delimiting their respective region where they recombine with a rate proper to each surface. Considering a solar cell structure with finite n and p-type regions of lengths; d n , and d p respectively, such that when injected the minority carriers can reach the corresponding ending surfaces, the saturation currents for electrons and holes are given by equations (4) and ( 5) respectively [24]. where n ni , n pi , n n0 and p p0 are the intrinsic carrier, the electron and the hole concentrations in the n-type and p-type regions respectively, D p , D n , τ p , τ n , L p , L n , S p and S n are the diffusion coefficients, lifetimes, diffusion lengths and surface recombination velocity of the minority carriers; holes and electrons, respectively, x on , and x op are the length of the depletion in the n and p region respectively.…”

Section: The Isolated Pn Junctionmentioning

confidence: 99%

“…Clearly, there is a value for the unknown parameter T 0 for which the function M(V SC , T x , T 0 ) becomes a constant equal to J 0AU (T x ). This occurs when to the unknown T 0 parameter is given a value that results to be equal to T x , the searched junction temperature [24][25][26]. It is highlighted that the above procedure does not constitutes a fit but rather a rigorous mathematical procedure based on the model of Shockley for the transistor currents.…”

Section: Temperature and Charge Transport Parameters Extractionmentioning

confidence: 99%

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On the importance of the junction temperature on obtaining the charge transport parameters of a solar cell

Mimila-Arroyo¹

2019

Semicond. Sci. Technol.

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The charge transport parameters (CTP) of a solar cell are extremely important as they provide the information required to do the fine tuning of its design and associated technology. This work demonstrates the necessity of knowing the junction temperature to extract them, other way their values might be wrong, misleading the device improvement efforts. Here the junction temperature and the CTP are extracted utilizing a dedicated structure similar to a bipolar junction transistor which allows to screen and separate the recombination current in the space charge region of the solar cell junction from that due to the injection-diffusion-recombination of minority carriers in its quasi-neutral regions. The additional pn junction is located beneath that of the solar cell, in such a way that the minority carriers injected into its base are able to reach the additional junction. Biasing the solar cell junction without biasing the additional one the neat separation of those currents is achieved. From the diffusion current reaching the additional junction the cell temperature is extracted as well as its diffusion saturation current. Then, with these two parameters the remaining ones are straightly obtained. Moreover, the current separation allows the cross verification of the extracted parameters. Additionally, the involved theory, model of Shockley, allows an estimation of the diffusion length and life time of the minority carriers in the solar cell base region. The method, applied to the n-GaInP/p-GaAs heterojunction solar cell shows that under the measurement conditions the true junction temperature was T 0 =296.343 K, the studied structure at this temperature has a diffusion saturation current of J 0D =3.9×10 −19 A cm −2 and a recombination current density of J 0R =1.9×10 −12 A cm −2 , diffusion length and life time of minority carriers in the base region of L n =0.46 μm and τ n =1.2×10 −10 s, respectively. These saturation current values compared with those obtained through the conventional mathematical fit are orders of magnitude different.

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Section: The Isolated Pn Junctionmentioning

confidence: 99%

Section: Temperature and Charge Transport Parameters Extractionmentioning

confidence: 99%