Sanyo's Challenges to the Development of High-efficiency HIT Solar Cells and the Expansion of HIT Business

Maruyama, Eiji; Terakawa, Akira; Taguchi, Mikio; Yoshimine, Yukihiro; Ide, Daisuke; Baba, Toshiaki; Shimizu, Masaki; Sakata, Hitoshi; Tanaka, Makoto

doi:10.1109/wcpec.2006.279743

Cited by 77 publications

(59 citation statements)

References 7 publications

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“…Both "front" HIT cells having an a-c HJ on the emitter side, 4 where the light enters and "double" HIT cells having HJs on both ends of the c-Si wafer 2,5,6 have been simulated. The cells have the following structure: ITO/P-a-Si:H/I-aSi:H/textured N-c-Si/N-c-Si BSF/metal ͑front HIT͒ 4 and ITO/P-a-Si:H/I-a-Si:H/textured N-c-Si/I-a-Si:H/N ++ -a-Si:H/ metal ͑double HIT͒.…”

Section: Simulation Of Experimental Resultsmentioning

confidence: 99%

“…The cells have the following structure: ITO/P-a-Si:H/I-aSi:H/textured N-c-Si/N-c-Si BSF/metal ͑front HIT͒ 4 and ITO/P-a-Si:H/I-a-Si:H/textured N-c-Si/I-a-Si:H/N ++ -a-Si:H/ metal ͑double HIT͒. 2,5,6 In Ref. 6, after depositing the undoped and doped a-Si:H layers on both ends of the c-Si wafer, ITO films were sputtered on both sides as the TCO layers, followed by screen-printed silver grid electrodes.…”

Section: Simulation Of Experimental Resultsmentioning

confidence: 99%

“…2͒ for a practical size of 100.4 cm 2 and 17.3% module efficiency 2 in HIT structures on N-type c-Si substrates, leading to industrial production already in 2003. Sanyo has focused on P-a-Si:H/N-c-Si HIT structures, [1][2][3][4][5][6] while European and U.S. groups have studied both P-a-Si:H/N-c-Si and N-a-Si:H/P-c-Si, structures, [7][8][9][10]30 with the maximum efficiency on P-type substrates reaching between 17% and 18%. 7,10,30 Recent studies have focused on the optimization of these devices in order to maximize the conversion efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…In recent editions of their cells. 1,2,6 however, record values of both the V oc and FF have been achieved and by simulating Sanyo cells at different stages of development in this article; we have tried to understand the reasons. We also know that Fuhs et al, 20 as early as in 1974, had already tried to combine c-Si and a-Si:H technology to produce HJ solar cells.…”

Section: Introductionmentioning

confidence: 99%

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Carrier transport and sensitivity issues in heterojunction with intrinsic thin layer solar cells on N-type crystalline silicon: A computer simulation study

Rahmouni¹,

Datta

Chatterjee

et al. 2010

Journal of Applied Physics

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Heterojunction with intrinsic thin layer or "HIT" solar cells are considered favorable for large-scale manufacturing of solar modules, as they combine the high efficiency of crystalline silicon ͑c-Si͒ solar cells, with the low cost of amorphous silicon technology. In this article, based on experimental data published by Sanyo, we simulate the performance of a series of HIT cells on N-type crystalline silicon substrates with hydrogenated amorphous silicon ͑a-Si:H͒ emitter layers, to gain insight into carrier transport and the general functioning of these devices. Both single and double HIT structures are modeled, beginning with the initial Sanyo cells having low open circuit voltages but high fill factors, right up to double HIT cells exhibiting record values for both parameters. The one-dimensional numerical modeling program "Amorphous Semiconductor Device Modeling Program" has been used for this purpose. We show that the simulations can correctly reproduce the electrical characteristics and temperature dependence for a set of devices with varying I-layer thickness. Under standard AM1.5 illumination, we show that the transport is dominated by the diffusion mechanism, similar to conventional P/N homojunction solar cells, and tunneling is not required to describe the performance of state-of-the art devices. Also modeling has been used to study the sensitivity of N-c-Si HIT solar cell performance to various parameters. We find that the solar cell output is particularly sensitive to the defect states on the surface of the c-Si wafer facing the emitter, to the indium tin oxide/P-a-Si:H front contact barrier height and to the band gap and activation energy of the P-a-Si:H emitter, while the I-a-Si:H layer is necessary to achieve both high V oc and fill factor, as it passivates the defects on the surface of the c-Si wafer. Finally, we describe in detail for most parameters how they affect current transport and cell properties.

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Section: Simulation Of Experimental Resultsmentioning

confidence: 99%

Section: Simulation Of Experimental Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Carrier transport and sensitivity issues in heterojunction with intrinsic thin layer solar cells on N-type crystalline silicon: A computer simulation study

Rahmouni¹,

Datta

Chatterjee

et al. 2010

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…The amorphous nature of a-Si:H leads to a low conductivity and high recombination rate of electron-holes pairs that are generated in the emitter, which limits the conversion of light at short wavelengths. [2,3] To leverage the progresses made in heterojunction solar cells while overcoming these limitations, it would be interesting to integrate new materials as front emitter, with a higher transparency, higher conductivity, and lower recombination rate.…”

Section: Introductionmentioning

confidence: 99%