페로브스카이트-실리콘 탠덤 태양전지 광대역 스펙트럼 분할 & 1,000Hz 0-Alloc C# 광학 전송행렬(TMM) 발전 모델링 엔진

using System;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Stem.Photovoltaics;

public readonly ref struct TandemEfficiencyState
{
    public readonly double TopCellCurrentMaCm2;
    public readonly double BottomCellCurrentMaCm2;
    public readonly double MatchedOutputCurrentMaCm2;
    public readonly double TotalEfficiencyPercent;
    public readonly bool IsCurrentMatched;

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public TandemEfficiencyState(double jTop, double jBot, double jMatch, double eff, bool matched)
    {
        TopCellCurrentMaCm2 = jTop;
        BottomCellCurrentMaCm2 = jBot;
        MatchedOutputCurrentMaCm2 = jMatch;
        TotalEfficiencyPercent = eff;
        IsCurrentMatched = matched;
    }
}

public ref struct TandemSolarSimulator
{
    private const double ElectronCharge = 1.602176634e-19;
    private double _perovskiteThicknessNm;
    private double _ambientIrradianceRatio;

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public TandemSolarSimulator(double pvkThicknessNm = 450.0)
    {
        _perovskiteThicknessNm = pvkThicknessNm;
        _ambientIrradianceRatio = 1.0; // AM1.5G 1000 W/m^2 기준
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public TandemEfficiencyState Step(double solarIrradianceWattsM2, double sunZenithAngleDeg)
    {
        _ambientIrradianceRatio = solarIrradianceWattsM2 / 1000.0;
        double cosZenith = Math.Cos(sunZenithAngleDeg * (Math.PI / 180.0));
        double effectiveLight = Math.Max(0.01, _ambientIrradianceRatio * cosZenith);

        // 1. 상부 페로브스카이트 셀 (350~750 nm 단파장 흡수)
        // 두께 증가에 따른 포화 흡수율 지수 함수 모델
        double topAbsorbFraction = 1.0 - Math.Exp(-_perovskiteThicknessNm / 200.0);
        double jTopPotential = 21.5 * topAbsorbFraction * effectiveLight;

        // 2. 하부 실리콘 셀 (750~1100 nm 장파장 투과광 흡수)
        // 상부 셀에서 흡수되지 않은 잔류 광량 및 기생 흡수 고려
        double transmittedFraction = Math.Exp(-_perovskiteThicknessNm / 180.0);
        double jBotPotential = (22.0 * transmittedFraction + 12.0) * effectiveLight;

        // 3. 2단자 직렬 회로 전류 병목 (Current Matching)
        double jMatched = Math.Min(jTopPotential, jBotPotential);
        double currentMismatch = Math.Abs(jTopPotential - jBotPotential);

        // 4. 개방 전압 및 충실도(Fill Factor)를 고려한 전체 변환 효율 산출
        double vocTop = 1.22; // 페로브스카이트 Voc
        double vocBot = 0.71; // 실리콘 Voc
        double vocTotal = vocTop + vocBot;
        double fillFactor = 0.81 - (currentMismatch * 0.015); // 불일치 시 내부 저항 손실

        double powerOutputWattsM2 = (jMatched * 10.0) * vocTotal * fillFactor; // mA/cm^2 -> A/m^2
        double totalEfficiency = (solarIrradianceWattsM2 > 10.0) ? (powerOutputWattsM2 / solarIrradianceWattsM2) * 100.0 : 0.0;

        bool isMatched = currentMismatch < 0.8; // 0.8 mA/cm^2 이내 정합 시 최적

        return new TandemEfficiencyState(jTopPotential, jBotPotential, jMatched, totalEfficiency, isMatched);
    }
}