capture a screen shot and show in the album folder

Hi... i don't know why i am having this issue .. but i have this script to capture the screen shot .. i applied it to a button ... the screen blink when i press the button but when i open the gallery of my tablet it doesn't show the captured screen shot ... :( .. when i test this code on PC or in unity editor it works fine.. it creates the folder at the folder "D:/Omer Hussain/Amigo-Projects/ChristmasStory/ScreenShots"; with the folder name "ScreenShots" and in that folder saves the image with image name "Christmas".... i want the same functionality on the device... i tried to find the folder as well the image with their names but device doesn't show anything but works fine on PC :/...

 using UnityEngine;
 using System.Collections;
 
 public class ScreenShot : MonoBehaviour {
 
     //string folderPath = "D:/Omer Hussain/Amigo-Projects/ChristmasStory/ScreenShots";
     string folderPath = "/storage/sdcard0/ChristmasShots";
     string fileName = "Christmas.png";
 
     void OnMouseDown()
     {
 
 
         if(!System.IO.Directory.Exists(folderPath))
             System.IO.Directory.CreateDirectory(folderPath);
         
         
         Application.CaptureScreenshot(folderPath + "/"+fileName);
     }
     
     }